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Bureau of Mines Information Circular/1985 



Primary Lead and Zinc Availability 
Market Economy Countries 

A Minerals Availability Program Appraisal 
By G. R. Peterson. K. E. Porter, and A. A. Soja 




UNITED STATES DEPARTMENT OF THE INTERIOR 



' AMINES 75TH A*^ 



Information Circular 9026 

1 1 



Primary Lead and Zinc Availability 
Market Economy Countries 

A Minerals Availability Program Appraisal 



By G. R. Peterson, K. E. Porter, and A. A. Soja 




UNITED STATES DEPARTMENT OF THE INTERIOR 

Donald Paul Hodel. Secretary 

BUREAU OF MINES 
Robert C. Horton, Director 



As the Nation's principal conservation agency, the Department ot the Interior 
has responsibility for most of our nationally owned public lands and natural 
resources. This includes fostering the wisest use of our land and water re- 
sources, protecting our fish and wildlife, preserving the environmental and 
cultural values of our national parks and historical places, and providing for 
the enjoyment of life through outdoor recreation. The Department assesses 
our energy and mineral resources and works to assure that their development is 
in the best interests of all our people. The Department also has a major re- 
sponsibility for American Indian reservation communities and for people who 
live in Island Territories under U.S. administration. 



THms 




Library of Congress Cataloging in Publication Data: 



Peterson, G. R. (Gary R.) 

Primary lead and zinc availability— market economy countries. 

(Information circular / United States Dept. of the Interior, Bureau 
of Mines ; 9026) 

Bibliography. 

Supt. of Docs, no.: I 28.27:9026. 

1. Lead industry and trade. 2. Zinc industry and trade. 3. Lead 
mines and mining. 4. Zinc mines and mining. I. Porter, K. E. (Ken- 
neth E.). II. Soja, A. A. (Audrey A.). III. Title. IV. Series: Infor- 
mation circular (United States. Bureau of Mines) ; 9026. 



*&2aS~U4— fHD9539.L4] 622s [338.2'744] 84-600357 



For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402 



,\ 



^ 

^ 



111 



PREFACE 



The Bureau of Mines is assessing the worldwide availability of nonfuel criti- 
cal minerals. The Bureau identifies, collects, compiles, and evaluates information 
on active, developed, and explored mines and deposits and mineral processing 
plants worldwide. Objectives are to classify domestic and foreign resources, to 
identify by cost evaluation resources that are reserves, and to prepare analyses of 
mineral availability. 

This report is part of a continuing series of reports that analyze the avail- 
ability of minerals from domestic and foreign sources. Questions about these re- 
ports should be addressed to Chief, Division of Minerals Availability, Bureau of 
Mines. 2401 E Street, NW., Washington, DC 20241. 















IV 



UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT 



g/t 


gram per metric ton 


pet 


percent 


kg 


kilogram 


St 


short ton 


km 


kilometer 


t 


metric ton 


lb 


pound 


tr oz 


troy ounce 


It 


long ton 


t/yr 


metric ton per year 


m 


meter 


yr 


year 



CONTENTS 



Page 

Preface iii 

Abstract 1 

Introduction 2 

World lead and zinc industries 3 

Lead industry 3 

Consumption 4 

Trade patterns 4 

Secondary sources 5 

Zinc industry 5 

Consumption 6 

Trade patterns 7 

Secondary sources 7 

Evaluation methodology 7 

Lead and zinc resources 9 

Geology of lead and zinc deposits 15 

Mining methods and operating costs 16 

Surface mining 17 

Underground mining 17 

Beneficiation methods and operating costs 18 

Smelting and refining 18 

Lead smelting 20 

Conventional blast furnace 20 

Imperial smelting furnace 21 

Lead refining 21 

Pyrometallurgical 22 

Electrolytic 22 



Page 

Zinc refining 22 

Electrolytic 22 

Imperial smelting furnace 23 

Electrothermic 23 

Horizontal retort 23 

Vertical retort 24 

Operating costs 25 

Mine and mill 25 

Lead mines and deposits 25 

Zinc mines and deposits 25 

Smelting and refining 26 

Total production costs 27 

Lead 27 

Zinc 28 

Capital costs 29 

Availability of lead and zinc 30 

Lead 30 

Zinc 32 

Importance of silver as a byproduct of lead 

and zinc production 37 

Demand for lead and zinc '. 39 

Conclusions 40 

References 40 

Appendix. — Geologic characteristics of major 
lead and zinc deposits in market 

economy countries 41 



ILLUSTRATIONS 



1. 
2. 
3. 

4. 
5. 

6. 

7. 

8. 

9. 
10. 
11. 
12. 
13. 
14. 

1.: 

16. 
17. 

18. 

10. 

20. 
21. 
22. 



Classification of mineral resources 2 

Flowchart of MAP evaluation procedure ' 3 

Percent share of contained lead in market economy countries 9 

Percent share of contained zinc in market economy countries 9 

Share of annual ore capacity, by mining method, for producing and undeveloped lead and zinc 

mines and deposits lg 

Basic flowsheet for a typical copper-lead-zinc flotation mill ....'.' 18 

Simplified schematic of a typical lead smelter using conventional blast furnace technology 20 

Simplified schematic of an Imperial smelting furnace plant 21 

Simplified schematic of pyrometallurgical lead refining 22 

Simplified schematic of an electrolytic zinc refinery 23 

Simplified schematic of an electrothermic zinc plant 24 

Simplified schematic of a vertical retort zinc plant 24 

Total recoverable lead from lead mines and deposits in market economy countries and the U.S 30 

vailability of lead as a byproduct of primary zinc mines and deposits in market economy countries 31 
Total recoverable lead from producing mines and undeveloped deposits in market economy countries 

and the United States 31 

il annual availability of primary lead from producing lead mines in market economy countries 

and the United States 32 

Potential annual availability of primary lead from undeveloped deposits in market economy countries 

and the United States 32 

Total recoverable zinc from market economy countries, the U.S., Australia, and Canada ..... ..... 33 

availability of zinc as a byproduct of primary lead mines and deposits in market economy coun- 
tries and the United States 33 

Total availability of zinc as a byproduct of primary copper mines and deposits in market economy 

countries 00 

Total recoverable zinc from producing mines and undeveloped deposits in market economy countries 

and the United States 34 

annual availability of zinc from producing zinc mines in market economy countries and the 

United States 35 



VI 

Page 

23. Potential annual availability of zinc from undeveloped deposits in market economy countries and the 

United States 35 

24. Total availability of lead from mines and deposits in market economy countries with byproduct silver 

at varying prices 35 

25. Total availability of zinc from mines and deposits in market economy countries with byproduct silver 

at varying prices 37 

TABLES 

1. World lead mine production, 1961, 1971, and 1981 4 

2. World primary and secondary lead production in 1981 4 

3. U.S. lead import, export, and consumption for 1980-81 5 

4. World zinc mine production, 1961, 1971, and 1981 6 

5. U.S. zinc import, export, and consumption for 1980-81 7 

6. Byproduct prices used in the economic evaluations 8 

7. Summary of demonstrated lead and zinc resource values 9 

8. Summary of January 1981 minable resource values for mines and deposits evaluated as lead properties, 

with minable resources and weighted-average feed grades 10 

9. Summary of January 1981 minable resource values for mines and deposits evaluated as lead prop- 

erties, with minable resources and weighted-average grades for byproduct zinc 10 

10. Summary of January 1981 resource values for mines and deposits evaluated as zinc properties, with 

minable resources and weighted- average feed grades 10 

11. Summary of January 1981 minable resource values for mines and deposits evaluated as zinc properties, 

with minable resources and weighted- average grades for byproduct lead 10 

12. Summary of January 1981 minable resource values for mines and deposits evaluated as copper proper- 

ties, with minable resources and weighted-average grades for byproduct lead 11 

13. Summary of January 1981 minable resource values for mines and deposits evaluated as copper 

properties, with minable resources and weighted- average grades for byproduct zinc 11 

14. Mines and deposits evaluated as lead operations 11 

15. Mines and deposits evaluated as zinc operations 12 

16. Mines and deposits evaluated as copper operations with lead and zinc as major byproducts 15 

17. Mining methods and costs for producing and undeveloped lead and zinc mines and deposits 17 

18. Estimated average mill capacity and operating cost 18 

19. Market economy country 1981 lead and zinc smelting and refining capacity, by region 18 

20. Comparison of 1968 and 1981 lead smelting and refining methods 18 

21. Comparison of 1958, 1968, and 1981 zinc refining methods 20 

22. Typical smelter and refinery recoveries and product grades 20 

23. Estimated mine and mill operating costs for producing and undeveloped lead mines and deposits . . 25 

24. Estimated mine and mill operating costs for producing and undeveloped zinc mines and deposits ... 26 

25. Typical smelter schedules 26 

26. Estimated total production costs for producing and undeveloped lead mines and deposits 27 

27. Estimated total production costs for producing and undeveloped zinc mines and deposits 28 

28. Capital costs for undeveloped lead and zinc deposits 29 

29. Comparison of estimated long-run average total costs of potential zinc metal production from pri- 

mary zinc mines and deposits 35 

30. Comparison of estimated zinc metal production as a byproduct from lead mines and deposits at the 

estimated long-run average total costs of primary lead production 36 

31. Comparison of estimated zinc metal production as a byproduct from copper mines and deposits at 

the estimated long-run average total costs of primary copper production 36 

32. Comparison of estimated long-run average total costs of potential lead metal production from pri- 

mary lead mines and deposits 36 

33. Comparison of estimated lead metal production as a byproduct of primary zinc mines and deposits at 

the estimated long-run average total costs of primary zinc production 36 

34. Comparison of estimated lead metal production as a byproduct from copper mines and deposits at the 

estimated long-run average total costs of primary copper production 37 

35. Total recoverable silver as a byproduct of potential lead and zinc production 37 

36. Weighted-average total cost of production per pound of lead at various prices of byproduct silver . . 38 

37. Weighted-average total cost of production per pound of zinc at various prices of byproduct silver . . 38 



PRIMARY LEAD AND ZINC AVAILABILITY-MARKET ECONOMY COUNTRIES 

A Minerals Availability Program Appraisal 

By G. R. Peterson, 1 K. E. Porter, 2 and A. A. Soja 3 



ABSTRACT 

To determine the availability of lead and zinc from demonstrated resources, 
the Bureau of Mines evaluated 235 mines and deposits in 31 market economy 
countries. Of the 235 mines and deposits evaluated for this study, 186 were 
evaluated as zinc operations. 30 as lead operations, and 19 as copper operations. 

Demonstrated lead-zinc resources of market economy countries in 1981 
were approximately 4.3 billion metric tons (t) of ore containing 221 million t of 
zinc and 97 million t of lead. Of these amounts, approximately 154 million t of 
zinc and 70 million t of lead are estimated to be recoverable. 

The analyses indicate that demonstrated resources in market economy coun- 
tries should be sufficient to satisfy projected demand for primary lead and zinc 
through the balance of the century. The U.S. lead industry will continue to have 
a comparative advantage over the rest of the world industry, barring any dras- 
tic increase in the cost of compliance with pollution control regulations. It appears 
that the comparative disadvantage faced by the U.S. zinc industry will probably 
intensify owing to the relative quantity of lower cost zinc resources in other 
countries, especially Canada, Australia, Mexico, and Peru. 



1 Mineral economist. 
' Mininc enjriDeer. 
* Economist. 
Minerals Availability Field Office, Bureau of Mines, Denver, CO. 



INTRODUCTION 



Rising production costs in combination with lag- 
ging demand and market prices for both lead and zinc 
have created serious economic problems for many lead 
and zinc producers worldwide. The purpose of this 
Bureau of Mines report is to evaluate the comparative 
costs of potential lead and zinc production from demon- 
strated resources of lead and zinc in the market 
economy countries. 4 This will provide an estimate of 
the costs (in constant January 1981 dollars) associated 
with potential supplies of primary lead and zinc, and 
illustrate the production potential of the United States 
compared with producers in other market economy 
countries. 

This study evaluates the potential availability of 
lead and zinc from 235 producing mines and unde- 
veloped deposits, with 186 mines and deposits evalu- 
ated as primary zinc operations ; 30 mines and deposits 
evaluated as primary lead operations; and 19 mines 
and deposits evaluated as primary copper operations. 
A complete listing of the 235 mines and deposits that 
were evaluated and their ownership is presented in the 
"Lead and Zinc Resources" section. The assignment of 
a particular commodity as the primary product, gen- 
erally based on that product providing the largest 
proportion of sales revenue at current (1981) market 
prices, was a necessary requirement of the evaluation 
process using a price determination model as described 
in the "Evaluation Methodology" section. 

Resource tonnage estimates for the lead and zinc 
mines and deposits evaluated for this report were 
made at the demonstrated resource level according to 
the mineral resource classification system (fig. 1) 
developed jointly by the Bureau and the U.S. Geologi- 
cal Surv ey (I). 5 It shou ld be kept in mind that re- 
ported demonstrated tonnage estimates for many lead 



4 Market economy countries are defined as all countries that are 
not considered centrally planned economy countries. Centrally 
planned economy countries are Albania, Bulgaria, China, Cuba, 
Czechoslovakia, German Democratic Republic, Hungary, Kam- 
puchea, Laos, Mongolia, North Korea, Poland, Romania, U.S.S.R., 
and Vietnam. 

6 Italic numbers in parentheses refer to items In the list of 
references preceding the appendix. 



and zinc deposits tend to be somewhat conservative. 
Many companies, particularly small ones, find it 
economically prohibitive to define resources beyond a 
5- or 10-yr planning horizon. 

The procedure of this study was to quantify the 
recoverable demonstrated resource and the engineering 
and economic parameters affecting actual or proposed 
production from the mines and deposits selected for 
evaluation. 

The flow of the Minerals Availability Program 
(MAP) evaluation process from deposit identification 
to development of availability information is illus- 
trated in figure 2. This flowchart demonstrates the 
various evaluation stages required to estimate the 
potential availability of primary lead and zinc metal 
from demonstrated geologic resources. The following 
factors had to be estimated before the total production 
potential of lead and/ or zinc from each mine and 
deposit could be ascertained: 

1. The approximate annual production potential of 
each mine or deposit over its life. 

2. The total mine and mill capital and operating 
costs. 

3. The cost of transporting concentrate from each 
mine to the appropriate smelter and the subsequent 
transportation from the smelter to the refinery if the 
refinery was at a separate location. 

4. The estimated smelting and refining charges for 
each commodity using typical smelter schedules for 
each major producing country. Smelter schedules for 
smelting and refining in countries outside of North 
America, Western Europe, or Japan were estimated 
using the major regions as models. Although an effort 
was made to simulate the actual flows from the mines 
through the smelting and refining stage, the scope of 
this study prohibits an attempt to exactly match the 
capacities of existing smelters and refineries. 

For currently producing operations, the designed 
mining and milling capacities and other available pro- 
duction specifics were used in this study. For unde- 
veloped or developing deposits, appropriate mining and 
processing methods and potential capacities were based 
on published plans from mining companies or were 



Cumulative 
production 



IDENTIFIED RESOURCES 



Demonstrated 



UNDISCOVERED RESOURCES 



Probability range 
(or) 



MARGINALLY 
ECONOMIC 



SUBECONOMIC 



+ 
+ 



Other 
occurrences 



Includes nonconventional and low-grade materials 



Figure 1. — Classification of mineral resources. 



■rtd 










i M -ierai t 
| ln(fosir<?S ' 
| LOC«t. On 1 

1 System 1 
i (MILS) | 
l data | 

MAP 

computer 
data 
base 


sec.: Dfl 














' - aje 

g 'je 
Mtm -«• on 


















COSI 










1 








Deposit 
repo*i 








MAP 

per man en i 

deposit 

lies 

























Dan 
selection 

and 
validation 



t««s 
royalties. 



Economtc 
analysis 



vn-iBoip 
and 



Sensitivity 
analysis 



ibintyfT . fe 



Analytical 

repotls 



tvailabil i. 
curves 



Analylica: 
reporls 



Figure 2. — Flowchart of MAP evaluation procedure. 



based on existing mines as models, and on current 
engineering principles. 

When available, actual mining capital and operat- 
ing costs were used. However, where actual cost data 
were not available, costs were either estimated using 
established engineering techniques, or developed using 
the Bureau's cost estimating system (CES), a com- 
puterized version of the Bureau's capital and operating 
cost estimating manual (2>. Domestic deposits were 
evaluated by personnel of the Bureau's Field Opera- 
tions Centers and foreign data collection and cost 
estimation were performed under contract by Pincock, 
Allen & Holt. Inc.. Tucson, AZ; personnel of the 
Bureau's Minerals Availability Field Office, Denver, 
CO, evaluated the data and performed the economic 
evaluation analyses. 

The following objectives served as guidelines 
pursuant to the conduct of this study: 



1. To determine the demonstrated resources of lead 
and zinc metal from all known significant deposits in 
market economy countries. Estimates of identified re- 
sources for lead and zinc are also mentioned ; however, 
in the availability analyses, only demonstrated re- 
sources are included. 

2. To evaluate the quantity and the average total 
costs of potential primary lead and zinc production 
from resources in market economy countries in rela- 
tion to physical, technological, political, and other 
factors that affect production from each mine or 
deposit. 

3. To aggregate and illustrate graphically total 
potential production of primary lead and zinc at the 
average total cost of each mining operation, including 
a 15-pct discounted-cash-fiow rate of return (DCF- 
ROR) on all investments. 



WORLD LEAD AND ZINC INDUSTRIES 



Although lead and zinc exhibit a geologic affinity 
for each other, their respective industries are distinct- 
ly different, each with its unique problems and pros- 
pects. The following sections are largely extracted from 
the 1983 Bureau of Mines Mineral Commodity Profiles 
for lead (3) and zinc U). 



LEAD INDUSTRY 

Lead was mined in about 50 countries during 
1981, but smelted to produce primary metal in only 35. 
There were 55 countries refining secondary lead. The 
United States continued to be the leading producer of 
both primary and secondary lead with production of 
438.000 t of primary and 641,000 t of secondary lead in 
1981. In primary refined lead production, the U.S.S.R. 
ranked second with an estimated 410,000 t, followed 
by Japan with 230,000 t, France with 210,000 t, and 



Australia with 208,000 t. The U.S.S.R. also ranked 
second in secondary lead production with an estimated 
220,000 t in 1981, followed by the United Kingdom 
with 198,000 t, the Federal Republic of Germany with 
158,000 t, and Italy with 92,000 t. World mine produc- 
tion, by country, for 1961, 1971, and 1981 is shown in 
table 1, and a comparison of world smelter and refinery 
production, by region, of primary and secondary lead 
for 1981 is shown in table 2. 

World mine production of contained lead in 1981 
amounted to 3.3 million t, which was only 64 pet of 
the total world demand. The United States had the 
greatest production, followed by the U.S.S.R., Aus- 
tralia, Canada, and Peru. Eleven countries, producing 
over 100,000 t each, accounted for 76 pet of the total 
world mine production. Approximately 350 mines in 
the world produced lead in 1981, in most cases as a 
coproduct or byproduct of other metals. 

Lead in the United States is produced from about 



Table 1.— World lead mine production, 1961, 1971, and 1981, metric tons of contained lead 



Area and country 



1961 



1971 



1981' 



Area and country 



1961 



1971 



1981' 



North America: 

Canada 165,616 392,970 332,100 

United States 237,61 5 524,861 445,500 

Latin America: 

Argentina 27,760 39,889 32,000 

Bolivia 20,301 23,125 16,700 

Brazil 13,608 27,837 29,600 

Chile 2,043 881 500 

Colombia 655 205 100 

Ecuador 111 200 

Guatamala 8,580 500 100 

Honduras 6,134 17,967 14,000 

Mexico 181,326 156,852 157,400 

Nicaragua 575 

Peru 136,400 165,816 186,700 

Europe: 

Austria 5,489 7,715 4,200 

Bulgaria 79,834 99,792 116,000 

Czechoslovakia 6,532 5,806 3,400 

Finland 3,120 4,739 1,600 

France 18,901 29,771 19,000 

German Democratic Rep 6,895 9,979 

Germany, Fed. Rep. of 49,577 41 ,102 21 ,600 

Greece 11,600 10,469 21,000 

Greenland 9,166 30,000 

Hungary 1,733 1,000 

Ireland 253 51,592 29,900 

Italy 47,719 31,600 20,600 

Norway 2,290 3,063 3,600 

Poland 38,200 62,778 50,400 

Portugal 25 1,383 

Romania 11,975 38,102 33,500 

Spain 79,709 70,151 83,000 



Europe — Continued 

Sweden 

U.S.S.R 

United Kingdom 

Yugoslavia 

Africa: 

Algeria 

Congo (Brazzaville). . 

Egypt 

Morocco 

Namibia 

Nigeria 

South Africa, Rep. of 

Tanzania 

Tunisia 

Zambia 

Asia: 

Burma 

China 

India 

Indonesia 

Iran 

Japan 

Korea, North 

Korea, Rep. of 

Pakistan 

Philippines 

Thailand 

Turkey 

Oceania: 

Australia 

New Zealand 



62,143 

353,808 

1,501 

96,682 

9,200 

875 

36 

88,270 

63,504 

6 

93 

351 

16,963 

15,382 

16,800 

1 90,000 

4,062 



14,969 

46,281 

50,000 

920 



101 

2,211 

1,089 

273,992 




79,455 

453,600 

1,497 

124,349 

4,717 

29 



78,001 

71,499 

215 





18,870 

27,670 

8,999 

1 100,000 

1,556 

200 

24,041 

70,587 

80,000 

16,544 

6 



1,473 

5,967 

403,562 
1,246 



Grand total 2,381 ,381 



3,395,607 



84,100 

410,000 

2,400 

120,000 

2,600 

3,500 



115,974 

59,100 

1,000 

98,900 



8,000 

14,000 

15,600 

155,000 

15,300 



10,000 

45,900 

100,000 

11,400 



1,100 

17,000 

8,000 

392,300 




3,344,855 



1 Estimated. 

NOTE. — Data may not add to totals shown because of independent rounding. 



Table 2. — World primary and secondary lead production In 
1981, thousand metric tons of contained lead 





Mine 


Smelter 


Refinery 


Secondary 
(refined) 


North America: 










United States. . . 


445.5 


495.3 


495.3 


641.1 


Canada 


332.1 


168.5 


168.5 


69.7 


Latin America 


437.3 


300.7 


294.4 


99.1 


Europe 


1,055.3 


1,221.7 


1,454.6 


1,033.2 


Africa 


312.1 


118.5 


118.5 


30.1 


Asia 


378.0 


487.1 


477.2 


162.9 


Oceania 


392.3 


367.2 


207.7 


44.5 


Total 


3,352.6 


3,159.0 


3,216.2 


2,080.6 



40 individual mines in 18 States. Lead concentrates 
are reduced to lead bullion at five smelters located in 
Missouri, Montana, and Texas. Three smelters in Mis- 
souri also have refineries, and there is one additional 
refinery in Nebraska that processes crude bullion from 
smelters in Montana and Texas. The Bunker Hill 
smelter-refinery in Bradley, ID, shut down indefinite- 
ly in 1981 as a result of unfavorable economic con- 
ditions. 

In 1981, the St. Joe Lead Co. operated six mines 
and four mills in southeast Missouri and a lead smelter 
at Herculaneum, MO; AMAX Lead Co. of Missouri 
operated a mine-mill-smeiter complex at Boss, MO, 
jointly owned by AMAX and Homestake Mining Co. 
ASARCO Incorporated operated mines in Colorado 
and New Mexico, smelters in El Paso, TX, East 
Helena, MT, and Glover, MO, and a lead refinery in 
Omaha, NE. The three ASARCO smelters and the 



Bunker Hill smelter treated both domestic and im- 
ported concentrates, whereas Missouri facilities norm- 
ally process domestic concentrates, mostly from Mis- 
souri. Other companies operating lead and lead-zinc 
mines included the Ozark Lead Co., a subsidiary of 
Kennecott Corp.; Hecla Mining Co.; and Cominco 
American Inc. 

Consumption 

Approximately 5.2 million t of lead in all forms 
was consumed worldwide in 1981, with the United 
States being the dominant consumer, accounting for 
22 pet of total consumption. The U.S. consumption 
share of refined lead and lead in antimonial lead 
(excluding other lead alloys and remelt) from 1978 to 
1981 averaged 31 pet of the total, compared with 40 
pet for Europe and 9 pet for Japan. Actual consump- 
tion for individual centrally planned economy coun- 
tries is not available but, overall, their consumption 
is estimated to be about 23 pet of the world's total for 
all types of lead metal ; slightly greater than the 1981 
percentage for the United States. 

Trade Patterns 

World trade from 1976 through 1981 averaged 
1.9 million t of lead per year contained in the form of 
ores and concentrates (35 pet), bullion (14 pet), and 
refined metal (51 pet). The figures exclude internal 
trade between the centrally planned economy coun- 
tries, but include estimates of trade between these 



countries and the market economy countries. During 
this period, Canada was the leader in exports of con- 
centrates, averaging 144,000 t/yr and Peru was second 
with 90,000 t yr. Japan and the Federal Republic of 
Germany were the leading importers of concentrates 
during the 1976-81 period. Japan's imports were pri- 
marily from Canada and Peru, and concentrate imports 
for the Federal Republic of Germany were from 
Sweden, Canada, Ireland, and Morocco. France, the 
third leading importer of lead concentrates, also de- 
pended heavily on Morocco, Ireland, and the Republic 
of South Africa. In 1981, Canada and Peru supplied 
64 pet cf the 59,000 t of concentrates imported by the 
United Stat 

The leading exporters of refined lead from 1976 
through 1981 were Australia with 156.000 t/yr, 
Canada with 123.600 t yr, and Mexico with 101.000 
t yr. These three countries exported 40 pet of the 
world total lead exports over the 6-yr period and, in 
1981. provided 94 pet of the U.S. import total of 
100,000 t of refined metal. The United States was the 
largest importer of lead metal during this period, 
averaging 159,500 t/yr, followed by Italy with an 
average of 148,000 t/yr. Italy depends primarily on 
the Federal Republic of Germany, Morocco, Australia, 
Namibia, and Mexico for refined metal. Although the 
United States is a significant importer of refined 
metal, imports do not constitute a major component 
of U.S. total supply. In 1981, the foreign component of 
U.S. total supply was about 4 pet in lead concentrates 
and 7 pet in refined metal. Domestic ores contributed 
about 31 pet to U.S. supply and recycled old scrap 
contributed about 40 pet. Industry stocks made up the 
remaining 18 pet. There have been no shipments of 
lead from the National Defense Stockpile since 1976. 
The U.S. import, export, and consumption levels for 
various forms of lead in 1980 and 1981 are shown in 
table 3. 

Secondary Sources 

Secondary lead is recovered from scrap, product 
and chemical industry wastes, lead refinery drosses, 
and other metallurgical wastes such as mattes, dust, 
slag, and residues. Most secondary lead is derived from 
wornout. damaged, or obsolete fabricated products 
such as battery plates and oxides, cable covering, pipe, 
and sheet. Such material is collected, smelted, and re- 
fined in secondary smelters to produce soft lead and 
antimonial lead or other various lead-base alloys. 
Additional secondary lead is recovered from process 
scrap, largely drosses and residues generated during 
the fabrication of lead products and recycled to sec- 
ondary smelters for production of refined ' ad. Some 
secondary lead materials are reused after remelting 
without refining, but an increasing * oportion is 
processed in refineries because of the need, in most 
uses, to meet customer product specifications. Second- 
ary materials have been the source for over 35 pet of 
the total world use of lead and for over 50 pet of U.S. 
requirements in recent years. The main source of 
secondary lead is automobile storage batteries that 
have been scrapped after use. In the United States and 
other industrialized countries, about 90 pet of the lead 



81,300 


100,108 


2,868 
950 


2,661 
474 


3,818 
115,029 


3,135 
130,898 



Table 3.— U.S. lead Import, export, and consumption for 
1980-81, metric tons of contained lead 

1980 1981 

IMPORT 

Ore, Hue dust, base bullion, and residues: 

Argentina 61 3,932 

Canada 3,232 1 ,972 

Chile 2,236 2,084 

Honduras 3,973 11,617 

Peru 18,141 6,299 

Other 2,268 1,751 

Total 29,911 27,655 

Metal (pigs and bars): 

Australia 10,844 9,080 

Canada 34,929 50,849 

Mexico 28,657 33,723 

Peru 3,298 2,907 

Other 3,532 3,549 

Total 

Reclaimed scrap 

Sheets, pipe, shot 

Total 

Total imports 

EXPORT 

Ore and concentrates 27,615 33,043 

Blocks, pig, anodes, etc.: 

Unwrought 147,356 14,484 

Unwrought alloys 9, 1 44 2,320 

Wrought lead and lead alloys > 7,958 6,516 

Scrap' 71,791 35,651 

Total 263,863 92,014 

CONSUMPTION ====== 

Apparent consumption 997,000 1 ,040,000 

' Lead content at 60 pet. 

NOTE. — Data may not add to totals shown because of independent rounding. 



used in the manufacture of storage batteries is re- 
cycled. 



ZINC INDUSTRY 

Changes in world mine and smelter production of 
zinc have led to changes in the zinc supply pattern of 
the United States, particularly during the last decade. 
The result has been an increasing reliance on foreign 
sources of zinc metal to satisfy domestic requirements. 
World zinc mine production for 1961, 1971, and 1981 
are shown in table 4. 

The United States, which was the largest zinc 
metal producer in the world from 1901 through 1971, 
has been dependent upon imports of concentrates for 
a substantial portion of smelter feed since the begin- 
ning of World War II. Domestic primary production 
of slab zinc reached a peak of 944,014 t in 1969, with 
a continuous decline in production since that time as 
10 domestic primary zinc smelters have been closed 
and only 2 new smelters were commissioned, 1 in 1976 
and 1 in 1978. Zinc oxide production from zinc fuming 
plants at the El Paso, East Helena, and Bunker Hill 
lead smelters has also been curtailed with the fuming 
furnaces at all three plants on temporary or indefinite 
closure. Because of this reduction in U.S. smelting 
capacity, the need for foreign concentrates has de- 
clined significantly, with imported refined zinc metal 
becoming a major factor in U.S. supply. 

World zinc metal production increased from about 
1 million t/yr in the middle 1930's to 6.1 million t in 



Table 4. — World zinc mine production, 1961, 1971, and 1981, metric tons of contained zinc 



Area and country 



1961 



1971 



198V 



Area and country 



1961 



1971 



1981' 



North America: 

Canada 

United States 

Latin America: 

Argentina 

Bolivia 

Brazil 

Chile 

Colombia 

Ecuador 

Guatamala 

Honduras 

Mexico 

Nicaragua 

Peru 

Europe: 

Austria 

Bulgaria 

Czechoslovakia 

Finland 

France 

German Democratic Rep. 

Germany, Fed. Rep. of . . 

Greece 

Greenland 

Hungary 

Ireland 

Italy. . P 

Norway 

Poland 

Portugal 

Romania 



401,979 
421,295 

30,210 

5,333 



162 

726 



7,926 

6,215 

266,973 



173,872 

6,034 
73,937 

( 2 ) 

46,597 

15,600 

6,985 

87,213 

17,547 

7,983 



167 

134,224 

9,331 

139,579 



( 2 ) 



1,267,582 
455,907 

43,864 

45,077 

16,920 

1,982 

112 

126 

506 

22,894 

264,972 

4,056 

318,078 

21 ,073 

79,834 

8,564 

50,888 

15,140 

9,979 

131,986 

14,210 



4,808 

87,545 

105,870 

10,717 

193,596 

2,046 

39,826 



1,097,200 
312,400 

30,000 

47,000 

103,000 

1,100 

100 

1,600 

500 

18,000 

211,600 



496,700 

18,200 

90,000 

7,200 

53,600 

37,400 



91,800 

26,800 

86,400 

2,000 

120,300 

41,500 

31 ,000 

146,500 



55,000 



Europe — Continued 

Spain 

Sweden 

U.S.S.R 

United Kingdom 

Yugoslavia 

Africa: 

Algeria 

Congo (Brazzaville). . 

Morocco 

Namibia 

Nigeria 

South Africa, Rep. of 

Tunisia 

Zaire 

Zambia 

Asia: 

Burma 

China 

India 

Iran 

Japan 

Korea, North 

Korea, Rep. of 

Philippines 

Thailand 

Turkey 

Vietnam 

Oceania: 

Australia 

New Zealand 



87,983 

75,201 

399,168 



59,883 

42,638 



40,780 

13,522 





3,396 

99,634 

45,433 

7,348 

'100,000 

5,080 

13,517 

168,262 

'80,000 

450 

3,313 

898 

2,000 



292,840 




87,541 

99,044 

650,462 



98,695 

15,797 

633 

12,338 

43,697 



158 

1 1 ,794 

109,227 

57,067 

4,003 

'100,000 

8,246 

58,061 

294,424 

'135,000 

28,161 

3,375 



18,933 



452,654 
1,969 



Grand total 3,420,144 



5,515,200 



180,000 
180,900 
790,000 
9,600 
117,900 

6,200 
3,000 
7,900 

29,600 
100 

87,172 
7,500 

63,300 

22,200 

4,500 

160,000 

31 ,600 

15,000 

242,042 

140,000 

56,500 

5,289 



30,721 

6,000 

508,400 
100 



5,832,424 



' Estimated. 2 Production data not available; estimates are included in total. 
NOTE. — Data may not add to totals shown because of independent rounding. 



1981. The leading metal producing countries in 1981 
were the U.S.S.R., Japan, Canada, the United States, 
Federal Republic of Germany, and Australia. Over the 
past 10 yr, Brazil, Peru, Canada, U.S.S.R., Mexico, 
Republic of Korea, India, and Netherlands increased 
metal production considerably, whereas production in 
the United States, Zambia, and Zaire declined. 

About one-half of the world's mine capacity in 
market economy countries is held by seven companies 
either through direct ownership, subsidiaries, or 
equity sharing. These companies are Noranda Mines 
Ltd., Cominco Ltd., and Kidd Creek Mines Ltd. 
(Canada) ; ASARCO Incorporated (United States) ; 
The Rio Tinto Zinc Corp. Ltd. (United Kingdom) ; 
Centromin (Peru) ; and Societe Generate de Belgique 
(Belgium). The largest zinc refining companies are 
Societe Generale de Belgique, The Rio Tinto Zinc 
Corp. Ltd., and Mitsui Mining & Smelting Co. Ltd. 
(Japan). 

Several large, vertically integrated firms with 
mines, smelters, and refineries are prominent in the 
U.S. primary zinc industry. The principal companies 
that operated both mines and smelters or refineries in 
1981 were Amax Zinc Co. Inc, ASARCO Incorporated, 
The Bunker Hill Co., Jersey Miniere Zinc Co., and St. 
Joe Resources Co. In 1981, these companies accounted 
for 86 pet of the primary slab zinc produced in the 
United States and 58 pet of the mine output. Cominco 
American Inc., The New Jersey Zinc Co., Ozark Lead 
Co., Hecla Mining Co., and United States Steel Corp. 
were other major mine producers in 1981, accounting 
for an additional 40 pet. The Bunker Hill complex 
closed indefinitely in December 1981 and has not re- 



opened. A number of zinc-producing mines closed in 
late 1981, 1982, and 1983 for economic reasons. 

Consumption 

World consumption of refined metallic zinc has 
grown more or less steadily over the past 50 yr. Slab 
zinc consumption in market economy countries at- 
tained its highest level, 4.9 million t in 1973, but has 
fluctuated below that level since that time. Consump- 
tion in 1982 was about 4.2 million t. The anemic state 
of the world economy, the introduction of thin-wall 
diecasting, weight-reduction programs in the auto- 
mobile industry, and substitution by alternate ma- 
terials, have adversely affected zinc consumption in 
recent years. 

Europe traditionally is the largest zinc-consuming 
area and, in 1981, accounted for about 36 pet of world 
consumption, followed by North America, 31 pet, and 
Asia, 26 pet. The United States has historically been 
the largest single consumer of zinc; however, its pro- 
portion of world consumption has declined. Of the total 
refined zinc metal consumed by market economy 
countries in 1981, the United States consumed 16 pet 
compared with 32 pet in 1960. On the other hand, 
Japan, because of its rapid industrial growth over the 
last two decades, was the second largest consumer of 
zinc in 1981, having increased its proportion of world 
consumption from 8 pet in 1960 to 12 pet in 1981. In 
general, the growth of zinc consumption has been more 
rapid in the newly industrializing countries, especially 
in Asia, than in the older industrialized countries. 



Trade Patterns 

Although the trend towards vertical integration 
in zinc mining countries has continued over the past 
decade, world trade in zinc concentrates continues to 
be large and in 1981 was estimated to be 1.9 million t. 
Concentrates are mainly exported by Canada, Peru, 
Australia, Sweden, and Ireland; importing countries 
are mainly Japan, the United States, and countries in 
Western Europe. Domestic imports of concentrate de- 
creased significantly in the early 1970's owing to 
numerous smelter closures. Imports of zinc in concen- 
trate by domestic smelters averaged 380,000 t/yr dur- 
ing the 1960-71 period, but have averaged only 160,000 
. through 1982. 

During 1981. world trade in slab zinc was esti- 
mated to be 1.7 million t. or about 30 pet of world 
refined zinc production. The largest slab zinc exporters 
were Canada, Australia. Belgium, Netherlands, Fin- 
land, and Federal Republic of Germany. Peru and 
Mexico have opened new smelters since 1980, and slab 
zinc exports from these countries are expected to 
increase substantially. The largest importers of slab 
zinc in 1981 were the United States, Federal Republic 
of Germany. United Kingdom, India, and France. 

The United States imports more than one-half of 
the zinc it consumes and typically has an import de- 
pendence exceeding 60 pet. Approximately 60 pet of 
the concentrate and metal imports are obtained from 
Canada and Mexico, and therefore, severe supply dis- 
ruption is not likely to occur. Canada has the world's 
largest zinc mine production and has the capacity to 
meet essentially the whole of U.S. import require- 
ments. A number of other countries, principally Peru, 
Spain, and Australia, supply the remainder of U.S. 
zinc imports. The U.S. import, export, and consumption 
levels for various forms of zinc in 1980 and 1981 are 
shown in table 5. 

Secondary Sources 

Recovery of zinc from old scrap, mainly in the 
form of diecastings, engravers plate, and brass and 



Table 5.— U.S. zinc Import, export, and consumption for 
1980-81, thousand metric tons of contained zinc 

1980 1981 

IMPORT 
Ore and concentrates: 

Canada 110 180 

Honduras 7 4 

Mexico 14 21 

Peru 40 29 

Other 1J ]2__ 

Total 182 246 

Metal (blocks, pigs and slabs): 

Australia 25 26 

Canada 280 309 

Finland 18 29 

Mexico 24 15 

Peru 4 43 

Spain 11 29 

Zaire NAp 29 

Other 48 132 

Total 

Total imports 

EXPORT 

Waste and scrap 

Ore and concentrates 

Total 

CONSUMPTION 

Apparent consumption 

Slab 811 841 

Ores 59 61 

Zinc scrap 133 149 

Other scrap 1 139 139 

Total 1,142 1,189 

NAp Not applicable. 

' Includes zinc contained in copper-, aluminum-, and magnesia-based 
scrap. 

NOTE. — Data may not add to totals shown because ol independent 
rounding. 



bronze currently represents from 6 to 8 pet of the total 
world supply. New scrap is principally zinc- and 
copper-base alloys from manufacturing operations 
and drosses and skimmings from galvanizing and 
diecasting operations. New scrap is either sold to 
smelters or processed as runaround scrap by the com- 
pany that generates it. The large use of zinc in gal- 
vanizing and in compounds in which the zinc is lost 
limits the potential for any increased recycling of old 
scrap. 



410 
' 592 


612 
858 


30 
54 


30 
54 


84 


84 



EVALUATION METHODOLOGY 



To determine the potential availability of lead 
and zinc, 235 mines and deposits in market economy 
countries were evaluated: 186 mines and deposits were 
evaluated with zinc as the primary commodity; 30 
mines and deposits were evaluated with lead as the 
primary commodity, and 19 mines and deposits were 
evaluated with copper as the primary commodity. 
Geologic and operating data were collected for each of 
the evaluated mines and deposits. These data included 
demonstrated and identified resource estimates, actual 
or estimated mine and mill operating capacities in- 
cluding future expansions and development plans when 
ted. estimated mine life based 00 production 
capacity and demonstrated resource, all capital and 
reinvestment co I ating costs for mining and 



milling, mass balances for each concentrate produced 
in the mill, and estimates of smelting and refining 
toll charges for each concentrate and the pay-fors 
(credits and deductions) associated with each com- 
modity treated. 

Although an effort was made to simulate the ac- 
tual flows from the mines through the smelting and 
refining stage, with the appropriate smelter charges 
and pay-fore associated with the particular smelter 
and refinery; the scope of this study does not attempt 
to exactly matrh the capacities of existing smelters 
and refineries. Smelting and refining charges and the 
pay-for schedules used in the study are for typical 
smelters and refineries within the particular region or 
country. For f-xample, one smelter schedule was used for 



all concentrates sent to the United States, another 
was used for all concentrates sent to Japan, and so 
forth. For undeveloped deposits, future materials 
flows were estimated based on historical patterns, and 
on estimates of where plants for future smelting and 
refining capacity is likely to be constructed. 

For each mine and deposit included in this 
evaluation, capital expenditures were estimated for 
exploration, acquisition, development, mine plant and 
equipment, and mill plant and equipment. The capital 
expenditures for mining and processing facilities in- 
clude the costs of stationary and mobile equipment, 
construction, engineering fees, infrastructure, and 
working capital. Infrastructure includes costs for 
access and haulage facilities, ports, water facilities, 
power supply, and personnel accommodations. Work- 
ing capital is a revolving cash fund required for cur- 
rent operating expenses such as labor, supplies, in- 
surance, and taxes. 

The total operating cost is a combination of direct 
and indirect costs. Direct operating costs include 
materials, utilities, direct and maintenance labor, and 
payroll overhead. Indirect operating costs include 
technical and clerical labor, administrative costs, 
facilities maintenance and supplies, and research. 
Other costs in the analysis are fixed charges, including 
local taxes, insurance, depreciation, deferred expenses, 
interest payments (if any), and return on investment. 

After production parameters and cost estimates 
were established for each mine and deposit, all of the 
operating data were entered into the supply analysis 
model (SAM). The Bureau developed the SAM (5) to 
perform discounted-cash-flow rate of return (DCF- 
ROR) analyses to determine the long-run constant 
dollar price at which the primary commodity must be 
sold (f.o.b. the smelter-refinery) to recover all costs of 
production including a prespecified DCFROR on all 
investments. The DCFROR is most commonly defined 
as the rate of return that makes the present worth of 
cash flow from an investment equal the present worth 
of all aftertax investments (6). 

For this study, a 15-pct DCFROR was considered 
the necessary rate of return to provide the incentive 
to develop a mineral property or to continue producing 
over the long run. The determined value for the pri- 
mary commodity price is equivalent to the average 
total cost of production for the operation over its pro- 
ducing life under the set of assumptions and conditions 
(e.g., mine plan, full capacity production, and a market 
for all output) necessary to make a full economic 
evaluation. If an operation has more than one product, 
the prices of the byproducts are assumed to be the 
market prices for the period of analysis, which for this 
study was January 1981. An exception was made for 
the byproduct prices for cobalt, gold, and silver, which 
were adjusted to reflect more representative prices 
over the past 3-yr period. The January 1981 prices for 



Table 6.— Byproduct prices used in the economic evaluations, 
January 1981 dollars 

Commodity and unit Pnce 

Barite st. . $65.00 

Cadmium lb . . 2.50 

Cobalt lb. . '7.00 

Copper lb . . .89 

Fluorspar t. . 140.00 

Germanium kg . . 1 ,060.00 

Gold tr oz. . '425.00 

Iron (pellets) It units . . .81 

Lead lb.. -34 

Manganese It units . . 1 - 70 

Silver tr oz. . l10 -00 

Sulfur t . . 1 1 7 - 50 

Tin lb.. 74 9 

Tungsten lb. . 14 - 7 ° 

Zinc lb.. 41 

1 Adjusted to reflect representative period average; January 1981 price was 
anomalously high. 



these three commodities were anomalously high. 
Revenues generated by byproducts are credited against 
the cost of production. The market prices for by- 
products used in the analysis are shown in table 6. 

The SAM system contains a separate tax records 
file for each particular State or nation, which includes 
all of the relevant tax parameters under which a min- 
ing firm would operate, such as corporate income taxes, 
property taxes, royalties, severance taxes, or other 
taxes that pertain to the production of lead or zinc. 
These tax parameters are applied against each mineral 
deposit under evaluation with the implicit assumption 
that each deposit represents a separate corporate en- 
tity. Other charges considered in the analysis include 
standard deductibles such as depreciation, depletion, 
deferred expenses, investment tax credits, and tax-loss 
carryforwards. The system also contains an additional 
file of economic indexes to allow for continuous updat- 
ing of cost estimates to a base date. The recently 
published Bureau of Mines report on the availability 
of lead and zinc — domestic (7), used 1981 cost esti- 
mate data updated to the base study date of January 
1982. This study uses the base date of January 1981 
since the data were collected for that year and it was 
felt that the limited cost-index data for certain coun- 
tries were too unreliable to update to January 1982. 
For this reason, the U.S. costs presented in this report 
differ slightly from those presented in the domestic 
lead and zinc report. 

Detailed cash-flow analyses are generated by the 
SAM system for each preproduction year of an opera- 
tion beginning with the initial year of the analysis, 
1981. Upon completion of the individual analysis for 
each mine and deposit, all properties were simultane- 
ously analyzed and aggregated onto the availability 
curves presented in the "Availability of Lead and 
Zinc" section of this report. 



LEAD AND ZINC RESOURCES 



Demonstrated lead-zinc resources of the 235 
mines and deposits evaluated in market economy 
countries in 1981 were approximately 4.3 billion t of 
ore containing 221 million t of zinc and 97 million t of 
lead. Of these amounts, approximately 153.7 million t 
of zinc and 70.4 million t of lead are estimated to be 
recoverable. At the identified resource level, approxi- 
mately 250 million t of zinc and 111 million t of lead 



are contained in 5.3 billion t of lead and zinc ores in 
market economy countries. An additional 24 million t 
of zinc and 33 million t of lead are contained as identi- 
fied resources in centrally planned economy countries. 

Demonstrated lead-zinc resources, by country, are 
shown in table 7. Percentage shares of contained lead, 
by country, are shown in figure 3, and percentage 
shares of contained zinc are shown in figure 4. Note 



Table 7. — Summary of demonstrated lead and zinc resource values in market economy countries, as of January 1981 



Mines- Resources 

Country deposits (ore). 10 3 1 

A:e-a 1 3.580 

Argentina 1 6.600 

Australia 15 468.588 

Austna 1 10,000 

Bolivia ... 2 2.365 

Brazil ... 2 23.237 

Bur-na 1 3.100 

Canada 42 760.880 

Finland . . 4 40,950 

France 5 16,816 

Germany. Fed. Rep ol 3 24.400 

Greece 2 20,000 

Greenland 1 3,738 

Honduras ... 1 7.200 

India 4 110,200 

Ireland 5 59.506 

Italy 5 32,900 

Japan 9 74.579 

Mexico 18 237.638 

Morocco 6 24,230 

Namibia 3 14,798 

Norway 1 12,050 

Peru .... 15 254.996 

Portugal 1 140.000 

Soutn Africa. Rep of 3 282.433 

Spain 6 194.260 

Sweden 5 65,900 

Turkey 3 33,358 

Zaire 1 49.550 

Zambia 1 1.741 

Total or average 167 2,979,592 

United States 68 1.354.892 

Grand total c average 235 4.334,484 
NOTE —Data may not add to totals shown because of independent rounding. 



Weighted av grade, pet 



Contained metal. 10 3 1 



Zinc 


Lead 


Zinc 


Lead 


5.56 


1.33 


199 


48 


7.60 


6.20 


502 


409 


9.01 


495 


42,247 


23.207 


4.80 


1.40 


480 


140 


9.05 


1.34 


214 


32 


8.43 


1,12 


1,960 


261 


5.00 


6.25 


155 


194 


6.34 


2.27 


48.258 


17,308 


2.72 


.08 


' 1,113 


31 


5.11 


2.15 


860 


362 


8.97 


246 


2,191 


588 


4.50 


350 


900 


700 


13.40 


4.40 


501 


165 


8.00 


4.20 


576 


302 


499 


1.97 


5,499 


2,168 


897 


2.04 


5,339 


1,216 


4.52 


1.44 


1,487 


475 


4.77 


.86 


3,561 


641 


3.52 


1.83 


8,380 


4,359 


.61 


689 


150 


1,670 


2.89 


3.20 


429 


473 


1.20 


.00 


145 





3.44 


1.13 


8,765 


2,881 


3.24 


1.23 


4,536 


1,722 


4.51 


1.87 


12,741 


5,287 


2,89 


1 24 


5,622 


2,414 


3.91 


336 


2,579 


2,215 


4.76 


12 


1,588 


40 


13.60 


.00 


6,739 





22.30 


11.30 


388 


197 



564 
3.91 



2.33 
201 



5 10 



2.22 



168,101 
52,949 



221,050 



69,515 
27,254 



96,769 





Figure 3. — Percent share 
economy countries. 



of contained lead in market 



Figure 4. — Percent share of contained zinc in market 
economy countries. 



10 



that the weighted* average ore grades include both 
primary and byproduct ore grades. Average zinc 
grades from mines and deposits evaluated as primary 
zinc operations are higher than the averages shown in 
table 7, as are the average lead grades from mines and 
deposits evaluated as primary lead mines. A more 



meaningful comparison of lead and zinc grades can be 
shown by presenting minable ore tonnages (recover- 
able ore) and actual feed grades (including dilution) 
for mines and deposits evaluated as primary zinc, 
lead, or copper operations. These data, by country, are 
presented in tables 8 through 13. 



Table 8. — Summary of January 1981 minable resource values 

for mines and deposits evaluated as lead properties, with 

minable resources and weighted-average feed grades 

r Mines- Resources, Grade, Contained 

country deposits 10 3 t pet. lead, 10 3 t 

Australia 1 5,950 12.60 750 

Canada 1 838 4.76 40 

France 1 7,389 2.54 188 

Mexico 2 7,914 6.65 447 

Morocco 5 22,363 6.87 1 ,537 

Namibia 1 6,300 6.98 440 

South Africa, Rep. of .. . 2 121,075 3.71 4,494 

Spain 1 1 ,830 5.00 92 

Sweden 2 34,930 4.18 1,459 

Total or average 16 208,589 4.53 9,445 

United States 14 337,108 5.62 18,931 

Grand total or av. . . 30 545,697 5.19 28,375 

1- 

NOTE. — Data may not add to totals shown because of independent 
rounding. 



Table 9. — Summary of January 1981 minable resource values 

for mines and deposits evaluated as lead properties, with 

minable resources and weighted-average grades for 

byproduct zinc 

_ . Mines- Resources, Grade, Contained 

™ deposits 10 3 t pet zinc, 10 3 t 

Australia 1 5,950 9.70 577 

France 1 7,389 .59 44 

Mexico 1 4,701 3.70 174 

Morocco 2 3,430 1 .46 51 

Namibia 1 6,300 1 .90 120 

South Africa, Rep. of .. . 2 121,075 1.24 1,498 

Sweden 1 32,000 .74 237 

Total or average 9 180,845 149 2,700 

United States 12 332,793 1.05 3,504 

Grand total or av. . . 21 513,638 1.21 6,204 

NOTE. — Data may not add to totals shown because of independent 
rounding. 



Table 10.— Summary of January 1981 minable resource values for mines and deposits evaluated as zinc properties, with minable 

resources and weighted-average feed grades 



Country 



Mines- 
deposits 



Resources 
10 3 t 



Grade, 
pet 



Contained 
zinc, 10 3 1 



Country 



Mines- 


Resources, 


Grade, 


Contained 


deposits 


10 3 t 


pet 


zinc, 10 3 t 


5 


32,900 


4.05 


1,334 


8 


62,560 


4.21 


2,636 


16 


220,938 


3.29 


7,263 


1 


1,500 


5.85 


88 


1 


5,078 


6.30 


320 


14 


100,401 


6.78 


6,808 


1 


103,451 


3.06 


3,166 


1 


143,570 


6.04 


8,672 


5 


173,676 


2.75 


4,775 


2 


25,288 


7.50 


1.898 


1 


698 


24.50 


171 


1 


32,550 


12.20 


3,971 


1 


2,067 


17.80 


368 


132 


2,232,296 


6.02 


134,494 


54 


1 ,024,463 


4.43 


45,441 


186 


3,256,759 


5.52 


179,935 



Algeria 1 3,381 5.00 169 

Argentina 1 6,967 6.84 477 

Australia 12 404,970 9.10 36,858 

Austria 1 10,000 3.80 380 

Bolivia 2 3,621 5.14 186 

Brazil 2 23,237 7.84 1 ,823 

Burma 1 3,100 4.00 124 

Canada 33 612,288 6.30 38,609 

Finland 2 28,523 2.68 765 

France 4 10,060 6.43 647 

Germany, Fed. Rep. of. . . 3 24,963 8.45 2,109 

Greece 2 20,000 4.05 810 

Greenland 1 3,177 13.40 426 

Honduras 1 7,200 7.20 518 

India 4 111 ,629 4.30 4,803 

Ireland 5 54,503 7.92 4,322 



Italy 

Japan 

Mexico 

Morocco 

Namibia 

Peru 

Portugal 

South Africa, Rep. of . 

Spain 

Sweden 

Turkey 

Zaire 

Zambia 

Total or average . . . 

United States 

Grand total or av . 



NOTE. — Data may not add to totals shown because of independent rounding. 



Table 11. — Summary of January 1981 minable resource values for mines and deposits evaluated as zinc properties, with minable 

resources and weighted-average grades for byproduct lead 



Country 



Mines- 
deposits 



Resources, 
10 3 t 



Grade, 
pet 



Contained 
lead, 10 3 t 



Country 



Mines- Resources, 
deposits 10 3 t 



Grade, 
pet 



Contained 
lead, 10 3 t 



Algeria 

Argentina 

Australia 

Austria 

Bolivia 

Brazil 

Burma 

Canada 

Finland 

France 

Germany, Fed. Rep. of. 

Greece 

Greenland 

Honduras 

India 

Ireland 



1 

1 
11 
1 
2 
1 
1 
26 
1 
4 
3 
2 
1 
1 
4 
5 



3,381 

6,967 

402,405 

10,000 

3,621 

17,613 

3,100 

540,894 

11,180 

10,060 

24,963 

20,000 

3,177 

7,200 

1 1 1 ,629 

54,503 



1.20 

5.58 

5.03 

1.10 

.66 

1.26 

5.00 

2.84 

.26 

.99 

2.27 

'3.15 

4.40 

3.80 

1.75 

1.80 



41 

389 

20,223 

110 

24 

222 

155 

15,361 

29 
100 
567 
630 
140 
274 
1,951 
983 



Italy 

Japan 

Mexico 

Morocco 

Namibia 

Peru 

Portugal 

South Africa, Rep. of. 

Spain 

Sweden 

Turkey 

Zambia 



Total or average 
United States 



Grand total or av 



5 
8 

15 
1 
1 

14 
1 
1 
5 
2 
1 
1 



120 
20 



140 



32,900 

62,560 

220,136 

1,500 

5,078 

100,401 

103,451 

143,570 

173,676 

25,288 

698 

2,067 



2,102,018 
354,390 



2,456,409 



1.31 
.74 
1.52 
1.35 
1.80 
2.77 
1.16 
.47 
1.13 
1.58 
1.20 
9.00 



2.51 
1.78 



2.40 



432 

464 

3,352 

20 

91 

2,777 

1,200 

675 

1,959 

399 

8 

186 



52,762 
6,295 



59,057 



NOTE. — Data may not add to totals shown because of independent rounding. 



A detailed breakdown of recoverable metal from 
lead and zinc resources is presented in the "Availa- 
bility of Lead and Zinc" section. Mines and deposits 
evaluated for this study, including ownership, status, 
and type, are listed in tables 14 through 16. 



Table 12. — Summary of January 1981 minable resource values 

for mines and deposits evaluated as copper properties, with 

minable resources and weighted-average grades for 

byproduct lead 



Country 



Australia 
Canaaa 
Japan 
Namibia 
Total or average 



Mmes- 
deposits 



Resources. 
10 3 t 



Grade, 
pet 



Contained 
lead. 10 3 1 



30.041 


1.18 


91.240 


18 


31.787 


86 


4.200 


2.14 



355 

164 

273 

90 



157.268 



56 



882 



11 



Table 13. — Summary of January 1981 minable resource values 

for mines and deposits evaluated as copper properties, with 

minable resources and weighted-average grades for 

byproduct zinc 







Mines- 


Resources. 


Grade. 


Contained 




deposits 


10 3 t 


pet 


zinc, 10 3 1 


Australia 




2 

7 


30.041 
145,228 


3.32 
3.94 


997 


Canada 




5,727 


Rnland 




2 


8.712 


1.05 


92 


Japan 






31,787 


3.22 


1.024 


Norway 






10.145 


1.10 


112 


Peru 






156.695 


1.05 


1.645 


South Africa. 


Rep of 




7,749 


2.07 


160 


Sweden 






7.600 


2.88 


219 


Turkey 


erage . 


2 


31.200 


3.11 


969 


Total or av 


18 


429.156 


2.55 


10.944 



NOTE —Data may not add to totals shown because of independent rounding 



Table 14. — Mines and deposits evaluated as lead operations 

(Property information as of January 1981) 



Ownership 



Status' 



Type 2 



Est ore capacity. 
10 3 tyr 


Mining methods 


102 


Cut and fill. 


168 


Do. 


136 


Room and pillar 


1,134 


Do. 


1.932 


Do 


1.134 


Do. 


2.058 


Do. 


200 


Do 


590 


Do 


952 


Do. 


1.769 


Do. 


867 


Do. 


454 


Do. 


212 


Combined methods. 


500 


Do. 


164 


Room and pillar. 


616 


Do. 


355 


Combined methods. 


235 


Cut and fill. 


150 


Combined methods 


200 


Do. 


84 


Overhand. 


400 


Room and pillar 


1,200 


Open pit. 


450 


Cut and fill. 


3.440 


Do 


1.800 


Do 


145 


Do 


1.500 


Room and pillar. 


300 


Do. 



UNITED STATES 

Colorado Bulldog Homestake Mining 

Idaho: Lucky Friday Hecla Mining Co 

Missoun 

Boss-Bixby Getty Oil-AZCON-Hanna Mining 

Bnjshy Creek Division St Joe Minerals Corp 

Buick AMAX Lead-Homestake Lead 

Fletcher Division St Joe Minerals Corp 

Frank R Milhken Kennecott (Ozark Lead Co.) . . 

Higdon-BonneTerre Bunker Hill-St. Joe Minerals 

Indian Creek St. Joe Minerals Corp 

Magmont Cominco American-Dresser 

Viburnum No 28 and No 29 St Joe Minerals Corp 

Viburnum No 35 do 

West Fork ASARCO 

Ulan Ontario United Park City-Noranda 

FOREIGN 

Australia North Broken Hill North Broken Hill Ltd 

Canada: Yava Barymin Exploration Ltd 

France L Argentiere Penarroya 

Mexico: 

La Encantada La Encantada S.A 

Rosano Industria Minera Mexico S.A 

Morocco 

Aouli-MibJaden Penarroya 

Dieted Aouam BRPM-Royal Astunenne-Vielle 

3 z ^ac~e- BRPM-Armico 

Royal Asturienne des Mines . . . 

ZeKla SODIM-ZELLIDJA-BRPM 

Namibia Tsumeto Tsumeb Corp. Ltd 

Soutn Afnca. Rep of 

Black Mountain Phelps Dodge-GFSA 

Broker Hi do 

jnares (El Cobrei Cia Minera la Cruz 

Sweden 

Bohden Metal AB 

Vassbo-GuttusjO do 



P 
P 

E 

P 

P 

P 

P 

PP 

P 

P 

P 

D 

D 

T 

P 
P 
P 

P 
D 

P 
P 
D 
P 
P 
P 

E 
P 
P 

P 
P 



1 D— developing deposit. E — explored deposit. P — producing mine. PP- 
1 C — surface and underground. S — surface. U — underground. 



■past producer, T — temporarily shut down 



12 



Table 15. — Mines and deposits evaluated as zinc operations 

(Property information as of January 1981) 



Ownership 



Status' 



Type 2 



Est ore capacity, 
10 3 t/yr 


Mining methods 


2,640 


Open pit. 


240 


Cut and fill. 


900 


Open pit. 


900 


Do. 


189 


Room and pillar 


381 


Sublevel open stope. 


272 


Shrinkage. 


525 


Combined methods. 


250 


Cut and fill. 


181 


Room and pillar. 


625 


Do. 


625 


Combined methods. 


1,656 


Open pit. 


192 


Room and pillar. 


1,797 


Block caving. 


324 


Combined methods. 


725 


Room and pillar. 


182 


Cut and fill. 


643 


Open stope. 


960 


Room and pillar 


113 


Do. 


490 


Do. 


544 


Do. 


272 


Do. 


400 


Combined methods. 


311 


Sublevel caving. 


709 


Do. 


228 


Room and pillar. 


625 


Combined methods. 


625 


Do. 


625 


Do. 


625 


Room and pillar. 


625 


Combined methods. 


625 


Room and pillar. 


2,041 


Do 


625 


Combined methods. 


275 


Do 


272 


Room and pillar. 


525 


Do. 


68 


Do. 


136 


Shrinkage. 


568 


Combined methods. 


400 


Do. 


625 


Room and pillar. 


625 


Do. 


400 


Do 


794 


Do. 


544 


Do. 


544 


Do. 


635 


Sublevel open stope. 


2,820 


Do. 


114 


Room and pillar. 


355 


Cut and fill. 


340 


Room and pillar. 


500 


Do. 


600 


Overhand square set. 


1,000 


Open stope. 


1,100 


Do. 


710 


Combined methods. 


710 


Open stope. 



UNITED STATES 
Alaska: 

Arctic Camp 

Greens Creek 

Lik 

Red Dog 

Colorado: 

Black Cloud 

Idarado 

Sunnyside 

Idaho: 

Bunker Hill 

Star Morning 

Illinois: Minerva No. 1-Spivey . . . 
Kentucky: 

Surkesville Project 

Fountain Run 

Maine: 

Bald Mountain 

Kerr American-Blue Hill 

Montana: Butte District Zinc 

Nevada: 

Ruby Hill Mine 

Ward Mountain 

New Jersey: Sterling 

New Mexico: Pinos Altos 

New York: 

Balmat 

Pierrepoint 

Pennsylvania: Friedensville Mine 
Tennessee: 

Beaver Creek 

Big War Creek 

Carthage Property 

Copperhill: 

Boyd North-South 

Eureka-Calloway 

Coy 

Cub Creek 

Cumberland 

Cumberland Deposit 

Cumberland Property 

East Gainsboro 

Gainesboro 

Gordonsville-Elmwood 

Hartsville 

Hartsville Area 

Idol 

Immel 

Jefferson City Mine 

Lost Creek 

New Market 

Pall Mall 

Right Fork 

Roaring River 

Stonewall 

Young 

Zinc 

Washington: 

Boundary Dam-Metaline Falls . 

Washington Zinc Unit 

Wisconsin: 

Crandon 

Crawhall-Elmo No. 3 

Pelican River 

Shullsburg-Bearhole 

FOREIGN 

Algeria: El Abed 

Argentina: El Aguilar 

Australia: 

Dugald River 

Elura 

Hilton 

Lady Loretta 



. Kennecott Copper Corp 

. Noranda-Others 

. Houston Oil & Minerals-GCO. 
. Cominco 



. ASARCO-Resurrection 

. Newmont Mining 

. Standard Metals 



Bunker Hill-Gulf Resources 
Bunker Hill-Hecla Mining . . 
Inverness Mining 



. Cominco-ASARCO-Others . 
. St. Joe Minerals Corp 



. Superior Oil Co 

. Kerr American-Black Hawk 
. Anaconda Copper Corp, . . . 



. Ruby Hill-Hecla-Others 

. Gulf Oil-Silver King Mianes . 

. New Jersey Zinc Co 

. Boliden-Exxon Minerals . . . 



St. Joe Zinc 

..do 

New Jersey Zinc Co. 



do. 
do. 



. St. Joe Minerals-Others 



. Cities Services Corp 

. ..do 

. ASARCO 

. New Jersey Zinc-Others 

. Jersey Miniere Zinc Co 

. Exxon Minerals 

. St Joe Minerals-Others 

Getty Oil-Tennessee Zinc Dev. . 

. New Jersey Zinc-Others 

. Jersey Miniere Zinc Co 

. Marathon Oil-J. F. Landers 

. Cominco American-NL Ind 

. New Jersey Zinc Co 

. ASARCO 

. New Jersey Zinc Co 

. ..do 

. ASARCO 

. ASARCO-Others 

. ASARCO 

. New Jersey Zinc Co.-AMAX Inc. 

. Jersey Miniere Zinc Co 

. ASARCO 

. US Steel Corp 



. Metaline-Washington Res. 
. Callahan Mining-Others . . 



. Exxon Minerals Corp. 
. Inspiration Mines 

Noranda Corp 

. Inspiration Mines 



SONAREM 

St. Joe Minerals Corp. 



. CRA Ltd 

. EZ Industries Ltd 

. Mount Isa Mines (MIM) Ltd 

. Triako Mines NL-MIM Holdings. 



E 
E 
E 
E 

P 

PP 

P 

PP 

P 

P 

E 
E 

E 

PP 

PP 

E 
E 
P 

E 

P 
D 
P 

P 

E 
E 

P 
P 
PP 

E 

E 

E 

E 

E 

E 

P 

E 

E 

P 

PP 

P 

P 

P 

E 

E 

E 

E 

PP 

P 

PP 
PP 

E 

PP 
E 
PP 

P 
P 

E 
D 
D 

E 



See footnotes at end of table. 



Table 15.— Mines and deposits evaluated as zinc operations— Continued 



13 



Ownership 



Status' 



Type ; 



Est ore capacity, 
10'tyr 


Mining methods 


7.000 


Combined methods. 


3.600 


Do 


1.100 


Do 


200 


Open stope. 


675 


Combined methods 


300 


Open pit. 


1,050 


Do. 


900 


Cut and fill. 


500 


Combined methods. 


245 


Cut and fill. 


161 


Shrinkage. 


825 


Room and pillar. 


420 


Bench (berm). 


310 


Do. 


350 


Cut and fill. 


3,400 


Open pit. 


3,500 


Cut and fill. 


300 


Do. 


2,800 


Do. 


181 


Sublevel open stope 


1,750' 


Cut and fill. 


529 


Room and pillar. 


450 


Combined methods 


222 


Open pit. 


350 


Do. 


286 


Room and pillar. 


496 


Combined methods. 


544 


Open pit. 


350 


Room and pillar. 


1,500 


Cut and fill. 


1,000 


Do. 


1,570 


Open stope. 


3,500 


Combined methods. 


733 


Open pit 


350 


Cut and fill. 


350 


Do 


508 


Sublevel open stope. 


1,476 


Cut and fill. 


495 


Do. 


562 


Room and pillar. 


3.290 


Open pit. 


749 


Cut and fill. 


315 


Do 


350 


Open pit. 


450 


Room and pillar. 


2,130 


Sublevel caving. 


700 


Cut and fill 


1,100 


Sublevel open stope. 


1,000 


Do 


260 


Open pit. 


260 


Cut and fill. 


182 


Sublevel open stope 


240 


Cut and fill. 


407 


Do. 


850 


Sublevel open stope 


277 


Cut and fill 


550 


Sublevel caving. 


800 


Do. 


640 


Room and pillar 


700 


Combined methods 


350 


Open pit. 


1.040 


Top slicing 


900 


Open stope. 


900 


Shrinkage 



FOREIGN— Continued 
Australia — Continued 

McArthur River 

Mount Isa 

New Broken Mill 

Que River 

Roseberry-Hercuies 

Teutonic Bc-e 

Woodlawn 

Zinc Corporation 
Austna Bleiberg-Kreuth 
Bolivia 

Mati'de 

Quechisia 

Paracatu 

Vaza^te 

• 3awdwm 
Canada: 
Abcoun-Barvue 
Anvil Range 
Brunswick No 12 
Buttle Lake 
Canbou Mine 



Cirque 

Daniels Harbor 

Detour Project 

F Group 

Gaiien 

Gays River 

Goidstream 

Goz Creek 

Great Slave Reef 

Hacked River 

Hatf Mile Lake 

Hearh Steele i Little River 

Joint Venture) 
Howard s Pass 
Izok Lake 
King Fissure 

Lyon Lake 

Martab: 

Mattaqami Lake 

B --'< 

=>0>nt 

Polans 

Praine Creek 

Resfjgouche 
Rotob Lake 
Sullivan 
Tom 
Finland: 
Pyhasalmi 

France 

Boden->ec 

Maiines 

Prxte-Aux-Moines 

Sa>m Saivy 
Germany Fed Reo of 

Grund 

Meggen 

Rammelsburg 
Greece: 

Mavres Petres-Madem Lakos 

Otymp»as 
Greenland Black Angel 
Honduras El Mochrto 
India 

Ambaji 

Mochja-Baiana 

Rajpura-Da'ba 

Zawarmaia-Barc* 



MIM Holdings Ltd 

MIM Ltd 

CRA Ltd 

Aberfoyle Ltd -Parmga Mining 

EZ Industries Ltd 

Seltrust-MIM Ltd 

St Joe-Phelps Dodge-CRA Ltd 

Zinc Corp Ltd 

Bleiberger Bergwerks Union 



COMIBOL 
do 



Mmeracao Morro Agudo 

Companhia Minena de Metais 
No 1 Mining Corp 



Abcourt Silver Mines-Noranda 

Cyprus Anvil Mining Corp 

Brunswick Mining and Milling 

Westmin Res. Ltd -Brascan Ltd. . . 

Anaconda Canada Ltd 

Hudson Bay Mining and Smelting. 

Cyprus Anvil-Hudson Bay 

Teck Corp 

Selco Mining Corp Ltd 

Noranda Mines Ltd 

Noranda-MacDonald 

Canada Wide Mines Ltd 

Noranda Mines Ltd 

Barrier Reef Resources Ltd 

Westmin-Dupont-Phihpp Bros 

Bathurst Norsemmes-Cominco 

Texasgulf Inc 

Heath Steele-Noranda-ASARCO 



Placer Dev -US Steel Corp 

Texasgulf Inc 

Internat Standard Resources 

Noranda Mines Ltd 

Noranda-Abitibi Mines Ltd 

Noranda Mines Ltd 

St Joseph-Sovereign Metals 

Mineral Resource Internat 

Pine Point Mines Ltd 

Cominco Ltd 

Cadillac Procan Explorations 

Placer Development 

Texasgulf-Arrow Inter Am-Bar 

Cominco Ltd 

Hudson Bay Mining and Smelting. 



Outokumpu Oy 

do 

BRGM 

Penarroya 

BRGM 

Penarroya 

Preussag AG Metail 
Sachtleben Bergbau Gmbh 
Preussag AG Metail 

Hellenic Chemical Prod Co 

do 
Cominco Ltd 
Rosario Resources-Amax Inc 

Gujarat Mineral Dev 
Hindustan Zinc. Ltd 

do 

do 



See footnotes at end of table 



14 



Table 15.— Mines and deposits evaluated as zinc operations — Continued 



Ownership 



Status 1 



Type 2 



Est ore capacity, 
1 3 t/yr 


Mining methods 


350 


Sublevel. 


700 


Cut and fill. 


600 


Combined methods. 


350 


Room and pillar. 


2,250 


Combined methods. 


350 


Sublevel open stope. 


950 


Sublevel caving. 


300 


Combined methods 


300 


Cut and fill. 


468 


Combined methods 


120 


Top slicing. 


240 


Do. 


444 


Cut and fill. 


329 


Sublevel open stope 


954 


Do. 


546 


Cut and fill. 


384 


Do. 


396 


Do. 


390 


Combined methods. 


300 


Open pit. 


140 


Open stope. 


124 


Sublevel caving. 


241 


Combined methods 


240 


Sublevel open stope 


756 


Cut and fill. 


218 


Combined methods. 


3.500 


Open pit. 


852 


Shrinkage. 


770 


Cut and fill. 


1,622 


Combined methods. 


312 


Cut and fill. 


1,026 


Shrinkage. 


1,034 


Combined methods. 


281 


Shrinkage. 


60 


Overhand. 


420 


Sublevel open stope 


460 


Combined methods. 


320 


Do. 


892 


Do 


2,113 


Do. 


432 


Room and pillar. 


273 


Cut and fill. 


600 


Combined methods. 


540 


Cut and fill. 


513 


Combined methods. 


350 


Do. 


636 


Do. 


406 


Cut and fill. 


300 


Sublevel open stope 


497 


Combined methods. 


429 


Cut and fill. 


3,000 


Sublevel open stope 


4,000 


Open pit. 


1,907 


Do. 


400 


Room and pillar. 


885 


Cut and fill. 


600 


Room and pillar. 


475 


Cut and fill. 


599 


Do. 


90 


Open pit. 


1,450 


Combined methods. 


240 


Sublevel open stope 



FOREIGN— Continued 
Ireland: 

Ballinalack Noranda-Barymin , 

Bula Bula Ltd. -Govt, of Ireland 

Mogul Kerr Addison-Silvermines 

Sabina-Tatestown Sabine-Messina-lrish Base Met. 

Tara (Navan) Tara Exp. -Govt, of Ireland 

Italy: 

Funtana Raminosa SAMIM 

Masua do 

Monteponi do 

Montevecchio do 

Raibl do 

Japan: 

Ezuri Dowa Mining Co. Ltd 

Fukazawa do 

Hosokura Mitsubishi Metal Corp 

Kamioka: 

Mozumi Mitsui Mining & Smelting 

Tochibora do 

Kosaka Dowa Mining Co. Ltd 

Nakatatsu Nippon Zinc Mining Co. Ltd. . . . 

Toyoha do 

Mexico: 

Charcas Industrial Minera Mexico 

Cuale Cia. Fresnillo S.A 



El Monte;EI Carrizal do 

El Tecolote Industrial Minera Mexico 

Fresnillo Cia. Fresnillo S.A 

La Negra Industrias Penoles S.A 

Naica Cia. Fresnillo S.A 

Parral Industrial Minera Mexico 

Real De Angeles Minera Real de Angeles 

San Francisco Del Oro Frisco S.A. de C.V 

San Martin Industrial Minera Mexico 

Santa Barbara do 

Santa Eulalia do 

Santa Maria de la Paz Min. Santa Maria de la Paz . . 

Taxco Industrial Minera Mexico 

Velardena do 

Morocco: Bou Madine Government of Morocco 

Namibia: Rosh Pinah Imcor Zinc (Pty.) Ltd 

Peru: 

Atacocha Cia. Minera Atacocha S.A. . . . 

Carahuacra Volcan Mines Co. . .' 

Casapalca CENTROMIN 

Cerro de Pasco do 

Hercules Cia. Minera Alianza S.A 

Huanzala Cia. Minera Santa Luisa S.A. 

Huaron Cia. Minera Huaron S.A 

Milpo Cia. Minera Milpo S.A 

Morococha CENTROMIN 

Raura Cia. Minera Raura S.A 

San Cristobal CENTROMIN 

San Vicente San Ignacio de Morococha . . 

Santander St. Joe Minerals 

Yauncocha CENTROMIN 

Portugal: Aljustrel Empresa Minera D'Aljustrel . . 

South Africa, Rep. of: Gamsberg Gamsberg Zinc Corp 

Spain: 

Aznalcollar Soc. Andalusa de Piritas S.A.. 

Cartagena Penarroya 

Reocin Asturiana De Zinc S.A 

Rubiales Exminesa 

Sotiel Minas de Almagresa S.A 

Sweden: 

Garpenberg Boliden 

Zinkgruven Soc. des Mines et Fonderies . 

Turkey: Aladag Cinko-Kursan Metal Sanayii . . 

Zaire: Kipushi Gecamines 

Zambia: Broken Hill Nchanga Consolidated 



E 
E 
P 
E 
P 

P 
P 
D 

E 
P 

P 
P 
P 

P 
P 
P 
P 
P 

P 
P 
P 
P 
P 
P 
P 
P 
D 
P 
P 
P 
P 
P 
P 
P 
E 
P 

P 
P 
P 
P 
P 
P 
P 
P 
P 
P 
P 
P 
P 
P 
P 
E 

P 
P 
P 
P 
D 

P 
P 
P 

P 
P 



U 
U 

u 
u 
u 

u 
u 
u 
u 
u 

u 
u 
u 

u 
u 
u 
u 
u 

u 
s 
u 
u 
u 
u 
u 
u 
s 
u 
u 
u 
u 
u 
u 
u 
u 
u 

u 
c 
u 
c 
u 
u 
u 
u 
u 
u 
c 
u 
u 
u 
u 
u 

s 
s 

u 
u 
u 

u 
u 
s 

u 
u 






1 D — developing deposit, E — explored deposit, P — producing mine, PP — past producer, T — temporarily shut down. 
2 C — surface and underground, S — surface, U — underground 



15 



Table 16.— Mines and deposits evaluated as copper operations with lead and zinc as major byproducts 

(Property information as of January 1981) 



Ownership 



Status' 



Type : 



Est ore capacity. 
10 J tyr 



Mining methods 



Australia 

Benambra 

CSA 
Canada 

Flin Flon 

Fox 

Geco 

High Lake 

Kidd C-eek 

Lake Dufauit Division 

Ruttan 
Finland 

Keretti 

Vuonos 
Japan Hanaoka 
Norway Tverreiellet 
Peru Antamma 

a Kombat-Asis West 
South Afnca Rep of Prieska 
Sweden Steke">|Okk 
Turkey 

Cayeii 

S rt 



Western Mining-British Petrol. 
Conzmc Riotinto of Australia 

Hudson Bay Mining and Smelting 
Sherntt Gordon Mines Ltd 

Noranda Mines Ltd 

Kennarctic Explorations 

Texasgulf. Inc 

Faiconbndge Copper Ltd 
Sherntt Gordon Mines Ltd 



Outokumpo Oy 

do 

Dowa Mining Co Ltd 

Folldal Verk AS 

Minero Peru 

Tsumeb Corp. Ltd 

Pneska Copper Mines Ltd. 
Boliden Metall AB 



Etibank 
do 



520 


Open pit. 


875 


Open stope. 


702 


Shrinkage. 


702 


Cut and fill. 


1.588 


Do. 


312 


Shrinkage. 


4.393 


Open stope. 


420 


Do 


3.175 


Do 


500 


Cut and fill. 


550 


Room and pillar. 


876 


Do. 


650 


Sublevel open stope 


10,500 


Open pit. 


350 


Combined methods. 


520 


Open stope. 


600 


Combined methods. 


600 


Cut and fill. 


705 


Shrinkage. 



' D — developing deposit. E — explored deposit. P — producing mine, PP — past producer, T — temporarily shut down 
1 C — surface and underground, S — surface. U — underground. 



GEOLOGY OF LEAD AND ZINC DEPOSITS 



The mineralogy of lead and zinc ores is relatively 
simple, with the sulfides galena (PbS) and sphalerite 
(ZnS) occurring as the major lead and zinc minerals, 
respectively. Most lead deposits contain galena asso- 
ciated with sphalerite, pyrite (FeS ._.), chalcopyrite 
(CuFeS i. and other base metal sulfides or sulfosalts, 
some of which are recovered to yield byproducts or co- 
products. Galena is usually associated with variable 
amounts of contained silver (argentiferous galena) ; 
galena low in silver is referred to as soft lead (8). 
Some galena ore bodies may be altered to cerussite 
(PbCO I, anglesite CPbSO,), or other oxidized lead 
minerals, but generally galena is resistant to weather- 
ing. Lead is a major constituent in several important 
deposit types, including stratabound, volcanic-sedi- 
mentary, replacement, veins, and contact metamorphic 
deposits. 

The major zinc deposits contain the zinc sulfide 
mineral, sphalerite. Most sphalerite has associated 
cadmium in quantities from traces to 2 pet, and small 
quantities of germanium, gallium, indium, and thal- 
lium. A few important zinc deposits contain oxide, 
carbonate, or silicate zinc minerals such as zincite 
CZnO). smithsonite CZnTO >, willemite fZm.SiO,), or 
hemimorphite 'Zn Si O. | OH i_«H.,0) ; commonly de- 
rived from the altered sulfide minerals. The two prin- 
cipal types of sulfide deposits are massive mixed sulfide 
ores in metamorphic rocks and irregular breccia or 
replacement stratabound deposits in carbonate rocka. 
A lesser number of sulfide deposits are classified as 
contact metamorphic. replacement, or vein deposits. 

The most ciimmon host rocks of stratabound lead 
and zinc deposits are limestones or dolomites. Sedi- 
mentary-structural features, such as reefs, facies 



changes, zones of minor jointing, or collapse breccias 
associated with ancient karst drainage, serve as loci 
for ore bodies within the favorable formations. 
Examples of such stratabound deposits are in the 
Southeast Missouri lead district; the Missouri-Okla- 
homa-Kansas district; the Upper Mississippi Valley 
district; the Pine Point deposit, Northwest Territory, 
Canada; the Laisvall deposit, Sweden; and the eastern 
Tennessee zinc deposits. 

Volcanic-sedimentary type deposits contain mas- 
sive sulfide bodies commonly interlayered with vol- 
canic or sedimentary rocks. Most such deposits are 
found in older folded and disturbed belts that have 
been severely metamorphosed. Their size can range 
from small lenses to enormous masses. The ore is 
commonly a fine-grained mixture of pyrite or pyrrho- 
tite, sphalerite, galena, and chalcopyrite, with minor 
amounts of nonmetallic and carbonate minerals. 
Examples of massive sulfide deposits are those near 
Bathurst, New Brunswick, Kidd Creek, and Sullivan 
in Canada; Broken Hill and Mount Isa, Australia; and 
Kuroko, Japan. 

Replacement deposits of lead and zinc are com- 
monly irregular hydrothermal type deposits in car- 
bonate rocks, but some also occur in quartzites or 
metamorphic rocks. The form and extent of the ore 
bodies are determined by the structural and strati- 
graphic elements that localized the replacement ac- 
tivity of the ore-bearing solutions. They include tabu- 
lar or cylindrical flat-lying bodies called mantos, 
pipelike structures that cross the bedding, and irregu- 
lar branching bedded deposits associated with veins. 
Some of the well-known replacement deposits include 
Cerro de Pasco, Peru; the silver-lead district of Cen- 



16 



tral Mexico; Tsumeb, Namibia; Tintic, Utah; and 
Leadville and Gilman districts, Colorado. 

Veins are the best known type of ore deposits. 
They are the most obvious and consequently were the 
first deposits to be exploited by ancient miners. The 
vein deposits are commonly situated in faults, joints, 
or at formational contacts. They contain ore minerals 
and gangue in varying amounts. Veins can be 1 to 10 
m long horizontally, and extend downwards hundreds 
of meters. Some of the better known vein systems 
occur in the Coeur d'Alene district in Idaho; the 
Silverton area of Colorado; Santa Barbara, Fresnillo, 
and Taxco Mines in Mexico; and the Harz Mountains, 
Clausthal, and Freiberg deposits in Germany. 

Contact metamorphic deposits are associated with 
igneous intrusions, which have either provided the 



solutions or emanations creating the deposit, or have 
altered and recrystallized (or replaced) a mineral 
deposit already present prior to the intrusion. De- 
posits range in size from small vein systems to massive 
pods hundreds of meters long. Although many deposits 
of this type are mined for other metals in the United 
States, only a few have produced significant amounts 
of lead, usually as a byproduct. The Kamioka, Obori, 
Chichibu, and Nakatatsu deposits in Japan are ex- 
amples of this type of deposit. 

A description of geological characteristics related 
to major important lead-zinc occurrences throughout 
the world is presented in the appendix for countries of 
six continents. Countries having a small percentage of 
the total world lead-zinc resource are not discussed. 



MINING METHODS AND OPERATING COSTS 



Lead and zinc ores are primarily exploited by 
underground mining methods. Of the 235 market 
economy deposits investigated, 211 were analyzed as 
underground operations, 134 of which were producing 
mines. Producing mines account for approximately 46 
pet of the zinc and 66 pet of the lead and silver poten- 
tially available from all deposits evaluated. 

The deposits were divided into six general mining 
method categories for analysis. These categories are 
surface, open stope, filled stope, caving, shrinkage 
stope, and combinations of underground categories. 
Figure 5 and table 17 show annual ore capacity in- 
formation by specific mining method for producing 
mines and undeveloped deposits. The 145 producing 
mines have a total ore capacity of 113 million t/yr 
with an average capacity of 780,000 t/yr. About 45 pet 
of this annual capacity is from small mines producing 
less than 1 million t of ore per year, and approximately 
85 pet of the small mine capacity is from underground 
operations. Open stope is the most common mining 



method, accounting for nearly 31 pet of the annual 
production capacity of producing mines. 

Undeveloped deposits have a potential production 
capacity of 84 million t of ore per year, 73 pet of 
which would likely be produced by underground meth- 
ods. As shown, production using underground methods 
would be spread nearly equally between combined, 
filled stope, and open stope methods with the re- 
mainder using caving and shrinkage methods. About 
42 pet of the potential capacity would be from small 
mines having capacities of less than 1 million t of ore 
per year. 

The selection of a mining method for the ex- 
ploitation of a mineralized body depends on a number 
of factors. A few of the most important are depth, 
geometry, structure, and attitude of the deposit. Addi- 
tional factors are strength of the mineralized body 
and surrounding wall rock. Climate and location may 
influence the decision to go with an underground 
rather than surface method because of severe weather 



PRODUCING MINES 
(Annual ore capacity 113 X I0 6 t) 



UNDEVELOPED DEPOSITS 
(Annual ore capacity 84 X I0 6 t) 





Figure 5. — Share of annual ore capacity, by mining method, for producing and 
undeveloped lead and zinc mines and deposits. 



17 



Table 17.— Mining methods and costs for producing and undeveloped lead and zinc mines and deposits 



Producing 



Undeveloped 



Mines- 
deposits 



Annual ore 
capacity. ^Q' t 

Average Total 



Cost per 

metric ton 

ot ore 



Mines- 
deposits 



Annual ore 
capacity, 10 3 1 

Average Total 



Cost per 

metric ton 
of ore 



Surface 
Open stope 
Riled slope 
Caving 
Shrinkage 

Combined underground 
Total or average 



11 
39 
34 
23 
4 
34 



1.500 
900 
590 
610 
360 
770 



16.500 
35.000 
20.070 
14.090 
1,420 
26.260 



$7.40 
12.70 
21 70 
17.40 
26 60 
23 70 



13 
33 
17 
7 
3 
17 



1.760 
500 
930 

1,310 
640 

1.060 



22.860 
16.390 
15.880 
9.160 
1.920 
18.040 



145 



780 



113.360 



1840 



90 



940 



84,250 



$9.30 
15 20 
24.70 
18.10 
20.20 
13.90 



17.90 



' Average stnppmg ratios — producirg mines. 4 4:1; undeveloped deposits. 3.3:1 Average operating cost per metric ton of 
matenal moved — producing mines. $1 40: undeveloped deposits, $2 20 



conditions or proximity to populated areas or bodies 
of water (Jakes, rivers, oceans, etc.). 



SURFACE MINING 

Surface mining requires a relatively shallow 
deposit with the stripping ratio (tons of waste rock to 
tons of orei normally under 5:1. A typical surface 
lead-zinc mine uses rotary blasthole drilling machines 
to drill the blasting rounds, which are charged with 
ANFO. The blasted ore is loaded with either diesel- 
electric shovels or front-end loaders into trucks for 
haulage to the mill. (At Pine Point in the Northwest 
Territories, Canada, a dragline is used to remove and 
dispose of blasted overburden prior to mining ore.) 
For surface operations, average mine recovery is 90 
pet with a 4-pct dilution factor. 

Eleven producing surface mines were evaluated 
for this study, five of which were small operations 
averaging 340.000 t/yr ore capacity while the six 
larger operations averaged nearly 2.5 million t/yr. 
Thirteen undeveloped deposits were evaluated as po- 
tential surface operations. Nine of these deposits 
averaged 510.000 t/yr ore capacity while the remaining 
four deposits averaged nearly 4.6 million t/yr. 

Surface mine operating costs are dependent on a 
wide range of variables, such as location and physical 
characteristics of the deposit and degree of mechani- 
zation. High mining costs per ton of ore for some 
mines are due to their remote location where costs of 
labor, supplies, and power are high. Large-capacity 
mines tend to be highly mechanized, efficient opera- 
tions. Smaller capacity mines, on the other hand, tend 
to be more labor intensive and require higher ore 
grades to operate profitably. An important cost factor 
irface mines is the stripping ratio, which meas- 
ures the tons of waste which must be mined to recover 
each ton of ore. 

The 11 producing mines have an average mining 
cost per metric ton of ore f?1.40 per metric 

ton of material) with an average stripping ratio of 
4.4:1 (table :"or the undeveloped deposits 

average S9.30 per metric ton of ore ($2.20 per metric 
ton of material) with an average stripping ratio of 
3.3:1. Estimated undeveloped mining per metric 

ton of ore average 25 pet greater than producing 
mines. 



UNDERGROUND MINING 

Underground mining method selection depends 
primarily on the attitude, depth, and dimensions of 
the mineralized body as well as the strength of the 
wall rock and mineralized body. The mining cycle for 
underground mining is similar from one mining 
method to another with type of equipment and degree 
of mechanization being the major variables. Drilling 
is performed by jackleg drills in smaller mines while 
jumbo drills are used in the larger, more mechanized 
mines. Dynamite, in the form of cartridges, is norm- 
ally used as the blasting agent, and it is initiated by 
electric blasting caps. Loading of broken ore and 
waste is performed by diesel or electric load-haul- 
dump (LHD) machines in the more mechanized mines 
while the smaller mines use overshot mucking ma- 
chines and manual shovel loading of ore carts. Trans- 
portation of ore and waste within the mine is pri- 
marily by truck or train with ore passes used to 
transfer material to the main haulage levels. In some 
cases, when the haul distance is relatively short, LHD 
machines perform both the loading and transportation 
functions. 

Access to underground mines is either by adit, 
incline, vertical shaft, or a combination of the three. 
Mode of access depends on the local topography and 
depth to the working areas. Shallow deposits or 
deposits in mountainous terrain may be accessed by 
adits or inclines while deeper deposits invariably are 
accessed by shafts. 

Open stope mining is characterized by strong and 
competent ore and country rock requiring a minimum 
of artificial support during the mining cycle. A hori- 
zontal to shallow dipping tabular ore body is developed 
by a series of interconnected rooms excavated in a 
regular or irregular pattern with pillars left for sup- 
port. This mining method is well suited for a high 
degree of mechanization because of large openings that 
make the access of large capacity equipment possible. 

Room-and-pillar and breast stoping are the princi- 
pal types r 'f open stope mini)n r u i 'I in lead and zinc 
mining. All of the Missouri lead-zinc mines and a 
majority of the Tennessee zinc mines use the room- 
and-pillar mining method. Open stope mining accounts 
cing and 19 pet of potential un- 
developed annual ore capacity in market economy 
countries. 



18 



Filled stope methods are used when the country 
rock or the mineralized body or both are too weak to 
allow excavated openings to remain open during the 
mining cycle. Some form of cut-and-fill operation is 
employed to provide the necessary support for the 
stope walls and back. Following the drilling, blasting, 
and loading operations in the mining cycle, the stope 
is backfilled with either waste rock or the sand portion 
of classified mill tailings. Both horizontal and inclined 
cut-and-fill stope methods and one square-set operation 
are included in the filled stope category. Approximate- 
ly 18 pet of producing and 19 pet of potential un- 
developed annual ore capacity from underground 
mines in market economy countries is from filled stope 
methods. 

Caving methods require the mineralized body to 
be weak enough to cave because of gravity once sup- 
port is removed. Drilling and blasting is restricted to 
development work. The loading and hauling operations 
are essentially the same as other underground methods 
with similar degrees of mechanization. Caving meth- 
ods provide 12 pet of the producing and 11 pet of the 
potential undeveloped annual ore capacity. 

Shrinkage stoping is similar to cut-and-fill stoping 
except that the broken rock filling the stope during 
the mining cycle is ore instead of waste or mill tail- 
ings. The ore is drilled and blasted in horizontal slices 
on a steeply dipping tabular ore body. The broken ore 
becomes the working floor for subsequent drilling. 
Sufficient ore is removed from the bottom of the stope 
to maintain an adequate working space from which to 



drill the next slice. One of the drawbacks to using this 
method for lead and zinc ores is that the high pyrite 
and other sulfide content of many deposits tends to 
oxidize in the stope causing poor flotation recovery in 
the mill. Only 1 pet of the producing and 2 pet of the 
proposed undeveloped annual ore capacity is from 
shrinkage method operations. 

Some mines use a combination of mining methods 
because of the difference in physical conditions from 
one part of the deposit to another. Mining methods 
may change through time because of economic con- 
siderations to maintain or improve the competitiveness 
of an operation. Approximately 23 pet of the produc- 
ing and 21 pet of the proposed undeveloped annual ore 
capacity is from mines that use or may use a com- 
bination of mining methods. 

Operating costs were also estimated for the 211 
underground lead and zinc mines and deposits, 134 
of which were producing as of January 1981. Indi- 
vidual deposit characteristics, such as location, stope 
width, depth, rock support requirements, and degree 
of mechanization all contribute to creating a wide 
range of operating costs. 

Among producing mines, open stope is the most 
common underground method with an average capacity 
of 900,000 t/yr and the lowest underground mine 
operating cost at $12.70 per metric ton. The shrinkage 
method, with an average mine operating cost of $26.60 
per metric ton of ore, is the highest cost method and 
has the lowest average capacity, 360,000 t/yr. 



BENEFICIATION METHODS AND OPERATING COSTS 



With the exception of the high-grade Sterling 
Mine in New Jersey and the Aladag Mine in Turkey, 
which produce direct shipping ore, all of the properties 
evaluated for this investigation use conventional 
crushing, grinding, and differential flotation as the 
primary beneficiation method. Individual flowsheets 
will differ in detail because of characteristics of the 
ore and number of concentrates recovered but all will 
have the same basic steps. Figure 6 is a simplified 
basic flowsheet for a typical lead-zinc-copper flotation 
mill. The ore is crushed, ground, and classified prior 
to flotation. Sometimes a heavy media separation cir- 
cuit follows the crushing circuit to remove waste prior 
to grinding. After flotation, the concentrates are 
thickened, filtered, dried, and stored for shipment. 

As many as three concentrates (lead, zinc, and 
copper), are generally produced in the flotation circuit. 
Zinc in the form of sphalerite is depressed, while 
copper in the form of chalcopyrite, and lead in the 
form of galena, are floated. The copper and lead con- 
centrates are then separated by floating copper fol- 
lowed by cleaning the copper and lead- concentrates. 
Tails from the first stage of flotation become the feed 
to the zinc flotation circuit. The zinc concentrate is 
cleaned and all three concentrates are subsequently 
thickened, filtered, and dried. 

When the grind sizes are very small (minus 200 



Run-of-mine ore 

i 



Crushing 
(staged) 



i 








ersize 


Tails 








Ov 




Grinding 




I 




Classification 










i 


i 


Tails 




Bulk copper-lead 
flotation 


Copper 
flotation 


Solid-liquid 
separation 










1 





Regrind 



Solid-liquid 
separation 



Lead concentrate 
to smelter 



Zinc 
flotation 



Copper concentrate 
to smelter 



Solid-liquid 
separation 



Final tailings 
to disposal 



Zinc concentrate 
to smelter 



Figure 6. — Basic flowsheet for a typical copper-lead-zinc 
flotation mill. 



19 



mesh"* because of fine sulfide grain sizes or intimate 
ore mineral associations, it is not practical to produce 
separate concentrates owing to poor liberation of the 
lead and zinc minerals. This situation would result in 
very poor recoveries and or very low quality concen- 
trates if separate concentrate production were at- 
tempted. In such cases, a bulk lead-zinc or lead-zinc- 
copper concentrate is produced. Further treatment 
would most likely be in an Imperial Smelting Corpora- 
tion blast furnace (Imperial smelting furnace), which 
is designed for handling bulk lead-zinc concentrates. 

Table 18 shows average estimated milling costs by 
ore capacity range. The number of concentrates pro- 
duced, grinding size, and power and labor rates are a 
few of the more important factors affecting these 
costs. 

Average mill operating costs range from $6 per 
metric ton of ore for operations with annual ore capa- 
cities greater than 2 million t to $8.60 per metric ton 
of ore for operations with annual ore capacities less 
than 500.000 t. 



Table 18. — Estimated average mill capacity and operating cost 

Mine ore capacity. Mines- Mill ore capacity Cost per metric 

10 s tyr deposits 10 3 tyr ton of ore 

<0.5 107 290 $8 60 

0.5 to 1.0 79 680 6.70 

1.0 to 2.0 27 1.370 6.10 

>2.0 21 3.580 6.00 

Total or av 234 840 6.60 



Most lead and zinc deposits in the United States 
are metallurgically simple and tend to be at the lower 
end of milling operating costs. With the exception of 
Ducktown, the Tennessee zinc deposits are essentially 
single mineral deposits and the Missouri lead-zinc 
deposits are primarily coarse-grained galena with low 
sphalerite content. The higher cost operations are 
primarily due to complex ores that require extensive 
grinding and separate flotation circuits to recover 
separate, clean, marketable concentrates of lead, zinc, 
and copper. 



SMELTING AND REFINING 



As of 1981. world lead smelter capacity was 
4.765.000 t and lead refinery capacity was 4,699,000 t 

p. 7). The market economy countries had an esti- 
mated 3.257.000 t of lead smelting and 3,228,000 t of 
lead refining capacity in 1981. Lead smelting tech- 
nologies include the conventional blast furnace, Im- 
perial smelting furnace, and electric furnace processes. 
Lead refining technologies use both pyrometallurgical 
and electrolytic processes. 

World zinc refining capacity in 1981 was 7,477,000 
of zinc, of which 5,839,000 t was from market 
economy countries. Zinc refining technologies utilize 
electrolytic, Imperial smelting furnace, electrothermic, 
and horizontal and vertical retort techniques for the 
recovery of zinc from concentrates. Table 19 shows a 
breakdown of capacities by smelting and refining 
methods by region. 

The relative importance of the various extractive 
metallurgical techniques used in the lead and zinc 
industry ha? changed significantly in the past two 
decades. Lead smelting by conventional blast furnace 
technology has increased from 80 to 89 pet from 1968 

"31 while electric furnace processes have decreased 
in relative importance by the same amount (table 20). 
The Imperial smelter furnace has remained unchanged 
in overall importance, accounting for about 8 pet of 
capacity. The trend in lead refining is to pyrometal- 
lurgical versus electrolytic, with an increase of 8 pet 
from 1968 to 1981 for the pyrometallurgical process 
production capacity. An estimated 78 pet of lead refin- 
ing capacity utilizes pyrometallurgical methods. 

Zinc extraction technology has undergone a major 
shift towards electrolytic refining away from hori- 



•Zlnc refining, aa uaed In tola Investlgotlon, refers primarily to 
electrolytic zinc refining but doea include some zinc recovered 
through pyrometallurgical Hmeltlog technology. 



zontal and vertical retort technology (table 21). The 
technological reasons for this shift are reduced re- 
covery, low energy efficiencies, and high levels of 
pollution effluents and emissions from the horizontal 
and vertical retorting plants. Electrolytic methods 

Table 19. — Market economy country 1981 lead and zinc smelt- 
ing and refining capacity, by region, thousand metric tons 
metal 

, . u Europe Africa Asia Oceania Total 

America America r 

Lead smeltm y (furnace): 

Conventional blast 1.212 207 717 150 235 380 2.901 

Impenal smelting 144 30 49 30 253 

Electric 55 48 103 

Total 1.212 207 916 180 332 410 3.257 

Lead refining: 

Pyrometallurgical 934 141 944 180 80 230 2.509 

Electrolytic 309 90 50 270 719 

Total 1.243 231 994 180 350 230 3.228 

Zinc refining: 

Electrolytic '1.280 294 1.804 213 848 260 4.699 

Impenal smelting furnace .. 389 34 136 70 629 

Electrothermic 77 25 18 125 245 

Horizontal retort 100 25 125 

Vertical retort 25 116 141 

Total 1.457 319 2,261 247 1,225 330 5.839 

' Includes capacity of Luis Potosi. Mexico, zinc refinery that started production in 1 982. 

Sources: Bureau of Mines data and reference 9 

Table 20.— Comparison of 1968 and 1981 lead smelting and 
refining methods, share of production, percent 

Process 1968 1981 

Smelting (furnace) 

Conventional blast 80 89 

Imperial smelting 8 8 

Electric 12 3 

Refining: 

Pyrometallurgical 70 78 

Electrolytic 30 22 

Sources Bureau of Mines data and reference 10 



20 



Table 21 .—Comparison of 1958, 1968, and 1981 zinc refining 
methods, share of production, percent 

Process 1958 1968 1981 

Electrolytic 50 56 81 

Imperial smelting furnace 8 11 11 

Electrothermic 3 4 4 

Horizontal retort 32 15 2 

Vertical retort 7 14 2 

Sources: Bureau of Mines data and reference 10. 

Table 22. — Typical smelter and refinery recoveries and product 
grades, percent 

Smelter Refinery 

Concentrate and commodity Recovery Grade Recovery Grade 

Zinc: 

Zinc NAp NAp 95 99.9 

Cadmium NAp NAp 90 99.95 

Gold NAp NAp 97 99.99 

Silver NAp NAp 97 99.99 

Lead NAp NAp 97 99.9 

Lead: 

Lead 97 98.5 99 99.9 

Gold 99 NAp 99.9 99.99 

Silver 99 NAp 99.9 99.99 

Copper: 

Copper 97 98.5 99 99.9 

Gold 99 NAp 99.9 99.99 

Silver 99 NAp 99.9 99.99 

Bulk lead-zinc: 1 

Lead 95 98.5 99 99.9 

Zinc 78-91 98.5 99 99.9 

Silver 99 NAp 99.9 99.99 

Gold 99 NAp 99.9 99.99 

NAp Not applicable. 1 Imperial smelting furnace. 



presently account for about 81 pet of market economy 
and 84 pet of U.S. zinc refining capacity. 

Typical smelter and refinery recoveries and prod- 
uct grades that can be expected for zinc, lead, copper, 
and bulk lead-zinc concentrates are listed in table 22. 
These are averages of values used in the evaluation of 
individual operations. Zinc recovery from zinc concen- 
trates ranged from 90 to 97 pet and lead recovery from 
lead concentrates ranged from 92 to 98 pet. The range 
in lead recoveries from a bulk lead-zinc or lead-zinc- 
copper concentrate processed by the Imperial smelting 
furnace did not differ significantly from that experi- 
enced with a simple lead concentrate, but zinc recovery 
from a bulk lead-zinc concentrate ranged considerably 
lower at 75 to 85 pet. This recovery could be increased 
by fuming the furnace slag for additional zinc, lead, 
and cadmium recovery. Copper recoveries generally 
range from 95 to 98 pet. 



LEAD SMELTING 

Conventional Blast Furnace 

The most widely used method for producing 
metallic lead is the blast furnace, which accounts for 
89 pet of market economy country lead production 
capacity (table 20). Figure 7 shows a simplified 
schematic of a conventional blast furnace operation. 
Lead sulfide concentrate feed is first sent through a 



Ottgases to 
atmosphere 



"Black" sulfuric 
acid to market 



Dust and tume 
to storage 



Sulfur dioxide 
removal 



Dust and fume 

collection 

(wet and/or dry) 



Offgases to 
atmosphere 



Dust and fume 
to storage 



Dry dust 
and 

fume collection 



High sulfur-dioxide 



content offgases 



Concentrate 


Feed 

preparation 

and 

blending 




Feed 
conditioning 

and 
agglomeration 


Limestone 


Iron ore 
Silica 


Slag 

Undersize sinter 




Dust and tume 




Low-sulfur -dioxide 
content offgases 



Sinter 

crushing 
and sizing 



1 



Blast 

furnance 
reduction 



Lead bullion 



to refiner 



Undersize sinter 

to storage s , ag , feed S | 0rage 

and disposal 
(optional zinc fuming) 

Figure 7. — Simplified schematic of a typical lead smelter using conventional blast furnace 
technology. 



21 



sintering plant to form sinter, a hard porous material 
suitable for charging to the blast furnace, and to 
remove most of the sulfur primarily as SO. gas. 
Generally, dust and fume containing lead, zinc, and 
cadmium oxide are collected in a baghouse and re- 
turned to the sinter plant. The sulfur dioxide in the 
offgas may report to a contact-type sulfuric acid plant 
or may be dispersed to the atmosphere through a tall 
smelter stack. 

The sinter is charged with coke and fed to the 
blast furnace where it is reduced to lead and collected 
at the hearth off of the furnace. Molten slag is tapped 
above the lead and is normally granulated for return 
to the sintering plant or to slag dumps. Crude lead is 
either tapped from the bottom of the settler or re- 
covered via a leadwell to a drossing ladle for delivery 
to the drossing section of the refinery. The locations of 
currently operating conventional lead blast furnace 
smelters in the United States are Boss, MO (AMAX- 
Homestake). Glover. MO (ASARCO), Herculaneum, 
MO CSt Joe). East Helena, MT (ASARCO), and El 
Paso, TX (ASARCO). 



through a sintering plant to form lead- and zinc-bear- 
ing sinter and partially remove the sulfur and cadmium 
in the offgases. The cadmium is contained in a sludge 
collected in the gas scrubbing system and recovered in 
a separate refinery. Sulfur dioxide is primarily con- 
verted to sulfuric acid with some loss through the 
stack. The lead-zinc sinter is treated in an Imperial 
smelting blast furnace where the lead and zinc are 
reduced to metal. Zinc is volatilized and collected in 
the condenser section while the lead is tapped from 
the bottom of the furnace as crude lead for further 
refining. Zinc recovery in the condenser is discussed 
in more detail in the "Zinc Refining" section of this 
report. 

There are currently eight Imperial smelting furn- 
aces operating in market economy countries. These 
are located in Australia, France, Federal Republic of 
Germany, Italy, Japan (2), United Kingdom, and 
Zambia. Brunswick Mining and Smelting Co. con- 
verted Canada's only Imperial smelting furnace, in 
New Brunswick, to a conventional lead blast furnace 
in 1972. 



Imperial Smelting Furnace 

Imperial smelting furnace technology was de- 
veloped in the 1950's to treat combined lead and zinc 
concentrates, bulk lead-zinc concentrates, and concen- 
trates of oxidized lead and zinc minerals. Products are 
standard zinc grade metal, silver-lead bullion, and 
cadmium-bearing sludge. Approximately 8 pet of the 
lead production capacity in market economy countries 
is treated by this method (table 20). 

The Imperial smelting furnace is basically a con- 
ventional lead blast furnace with a zinc recovery sec- 
tion added (fig. 81. The concentrate feed is first sent 



LEAD REFINING 

The purpose of lead refining is to produce refined 
lead (99.99 pet Pb) and to recover metal byproducts. 
Two methods of lead refining, pyrometallurgical and 
electrolytic, are in use in the lead industry. The pyro- 
metallurgical method accounts for approximately 78 
pet of market economy country primary lead refining 
capacity (table 20). The electrolytic refining method, 
used in Canada, Italy, Japan, and Peru makes up the 
remaining 22 pet capacity. A brief description of these 
two processes follows. 



Lead a 
conce 


nd zinc 
■Urates 






Gas to 
atmosphere 
















4 




Sinter 
machine 


Oftgas dust 
removal system 




Sulfuric acid 
plant 




Preheated 


coke — • 








1 


Sulfuric acid 
to market 




Imperial smelting 
blast turnance 




llion 


- 


Offgas scrubbing 
system 










Z 


nc vapor 1 


to relmery 
► Slag to dump 

: Lead 










Lead splash 
condenser 






t 






Cooling 
launder, lead-zinc 
separation bath 


K 


EY 
Solid 
Liquid 
Gas 








Zmc 

» 






Zmc holding 
bath 






♦ 






Zmc 






Slab 


r 





Figure 8. — Simplified schematic of an Imperial smelting furnace plant. 



22 



Pyrometallurgical 



Electrolytic 



Pyrometallurgical refining starts with the copper 
drossing of molten crude lead to remove copper as a 
result of cooling and treatment with elemental sulfur. 
The next step is the softening step, which removes 
any impurities of antimony, arsenic, and tin. Oxygen- 
enriched air is bubbled through the molten bullion to 
form a dross comprising lead oxide with the oxides of 
these elements. The dross is treated at the refinery in 
a barrel furnace with coke to recover the lead and to 
produce an antimony-rich slag. These first two steps 
are normally performed as part of the blast furnace 
operation at the smelter for convenience even though 
they are the first steps in the lead refining process. 

Next, the molten bullion is desilverized by adding 
zinc. Silver and gold form an alloy with the zinc, 
which floats to the top of the melt as a crust where it 
is skimmed off. The zinc crusts are retorted to recover 
the zinc by volatilization. The remaining material, 
which comprises lead, silver, and gold, is roasted in a 
cupeling furnace and the lead is oxidized to litharge. 
The litharge is returned to the blast furnace and the 
remaining gold-silver dore is sent elsewhere for part- 
ing. 

The zinc remaining in the bullion after desilveri- 
zation is normally removed by vacuum distillation for 
reuse in the desilverization process. The final refining 
step is accomplished by adding caustic soda to remove 
any remaining antimony and zinc; the dross thus 
formed is recycled to the sinter plant. The final lead 
product is 99.99+ pet lead and is cast into ingots or 
pigs for shipment to market. A simplified flowsheet for 
pyrometallurgical refining is shown in figure 9. 



Electrolytic lead refining starts with the decop- 
perized molten bullion from the blast furnace being 
cast into anodes. Refined lead, usually in the form of 
rejected bars or blocks, is cast into the cathode starter 
sheets (although other metals, such as aluminum can 
also be used for the cathode starter sheets). The 
anodes and cathodes are placed in the electrolytic cells, 
and the cells are filled with electrolyte, normally hydro- 
fluosilicic acid and lead fluosilicate. Electric current is 
applied and it passes from the anodes through the 
electrolyte to the cathodes. Lead is transferred from 
the anodes to the cathodes during this process. Finish- 
ed cathodes grading 99.99+ pet lead are melted and 
cast into shapes for market. Slimes with high values 
of antimony, bismuth, silver, gold, and some residual 
lead adhere to the scrap anodes. The slimes are re- 
moved from the anodes and sent elsewhere for further 
treatment, and the scrap anodes are returned to the 
smelter. 



ZINC REFINING 
Electrolytic 

Electrolytic refining accounts for over 80 pet 
(table 21) of the current zinc production capacity in 
market economy countries. Zinc sulfides, primarily in 
the form of sphalerite, are roasted (usually in fluidized 
bed roasters) to convert the sulfides to an acid-soluble 
sulfate and convert the sulfur to sulfur dioxide. This 
sulfur dioxide is removed with the roaster offgases 



c E 



Bullion 
Irom smelter 



I J 



Copper 



removal 



Soda ash 
Coke 



Copper 

rever- 

beratory 

furnance 



Anlimony 



removal 
—i 1 — 



* 



Slag 



= E 



■ 
p 


J 

Re 


eye 


le 2inc 


I 1 




t 


1 






I 


Silver 




Zinc 




Bismuth 


removal 


^ 




removal 




removal 


<7) 5 


i 




o 

c 

>« 










Zinc 




0> 




retorts 
















Bismuth 








> 






refinery 















Final 
cleanup 
casting 



Refined 
lead 



E a ^ 




oi en 
E "> 



Figure 9. — Simplified schematic of pyrometallurgical lead refining. 



23 



and treated in a contact-type acid plant to produce 
sulfuric acid. Calcine formed by roasting is treated in 
a sulfuric acid leach plant. Residues that settle out as 
a sludge in the leach plant are treated separately for 
the recovery of copper, cadmium, lead, silver, cobalt, 
and tin. The solution containing dissolved zinc is puri- 
fied through several stages to remove residual copper 
and cadmium prior to electrowinning. The purified 
leach solution is mixed with electrolyte and undergoes 
the electrolysis process in electrolytic cells in similar 
fashion as described in the "Lead Refining" section. 
The electrolytic zinc process differs from the lead 
process in that the transfer of zinc to the cathode is 
effected from the electrolytic solution rather than the 
anode. The anodes in an electrolytic zinc plant are 
fabricated from sheets containing 99 pet lead and 1 
pet silver. The cathode starter sheets are normally 
fabricated from aluminum sheet. The cathodes (which 
grade 99.99-t- pet zinc) are stripped, melted, and cast 
into shapes for market. A simplified flowsheet of the 
refining process is shown in figure 10. 



Zinc suilide 
concentrate 



Gas lo 
atmosphere 



I 








■— 


* 


O'igas Oust 
removal system 




» 










(caicme) 






t 




» 




seca^ation 




*c - eacr> 
(residue) 


• 






Solution P u 

Doooe. m 


iron 
oreoD'iation 




t 


i 




alio" 




Sond-Howd 

11 2liO<"i 



Suilunc acid 
plant 



. I 



Sui'unc acid 
to market 



t -ODoer 
* sreciD'Taie 



Solution DiS'fiCat'On 
(cadmium removal) 



5 ~, - - z - - 



_L_ 



1 e r^' o*X'**catKK! 
i- ,--_ »-• -:- . >-ie- ' 

I" 
- removal) 



r - 9u0 



~~ 



Leacn residue 

(lead, silver) 
to ieao smelter 



, Cadmium orecioitate 
to cadmium pianl 



■ 









1 




to Cisoosai 


Z-nc 

eiect'ow*- 


-■■ 




Scent electrolyte 



Sol.d or DulD 

Liouid 

Gas 



...... . _ ,. . f . . 



Figure 10. — Simplified schematic of an electrolytic zinc 
refinery. 



Imperial Smelting Furnace 

The Imperial smelting furnace process provides 
11 pet of market economy country zinc capacity (table 
21 "i. The lead recovery portion of this extraction was 
discussed previously. In this process, the zinc vapor is 
removed from the top of the lead blast furnace and 
passed through a condenser where the zinc is mixed 
into a molten lead spray. The molten lead-zinc mixture 
is cooled until the zinc separates from the lead and 
rises to the top of the holding tank. Zinc is recovered 
as prime western grade (98.0 to 98.5 pet zinc) which 
can be further refined by distillation to special high- 
grade specifications equal to electrolytic zinc (99.99 
pet zinc). The molten lead is recycled to the condenser. 
This method of zinc extraction provides a lower zinc 
recovery (approximately 96 pet) than the electrolytic 
process but provides the advantage of being able to 
treat lead-zinc ores that do not respond well to differ- 
ential flotation and the ability to recover the lead and 
silver values in zinc concentrates in a single process, 
whereas the electrolytic process must rely on retreat- 
ment of lead and silver residues in a blast furnace. 

Electrothermic 

The electrothermic process for zinc extraction 
was first developed by St. Joe Minerals Corp. and put 
into commercial operation during 1930 at Monaca. 
PA. The relative importance of this method has re- 
mained the same over the last two decades at 4 pet 
of world market economy country zinc extraction 
capacity (table 21). The zinc sulfide concentrate is 
first roasted then sintered in preparation for the 
charging of the resistance-type electric furnaces; lead 
and cadmium are removed during roasting and sinter- 
ing. The flow of current through the sintered ore and 
coke charge develops the energy required for smelting 
at the reaction sites. To produce zinc oxide, the furn- 
ace vapors are oxidized with air. or to produce zinc 
metal the furnace vapors are bubbled through a zinc 
bath where the zinc is condensed. A simplified flow- 
sheet for the electrothermic process is presented in 
figure 11. 

Horizontal Retort 

The horizontal retort process is one of the oldest 
methods used for zinc metal recovery with commercial 
adaptation as early as 1800. This process represented 
only 2 pet of market economy country zinc production 
capacity in 1981 as compared to 32 pet in 1958 (table 
21). The decline in use is primarily the result of in- 
creased labor and energy costs, and the control of 
particulate emissions. 

Zinc sulfide concentrates are first calcined in mul- 
tiple hearth roasters. Roaster gases are cleaned in 
electrostatic precipitators and sent to an acid plant to 
produce sulfuric acid or arc discharged to the at- 
mosphere through the stack. The calcine is intered to 
produce a sinter product suitable for feed to the 
horizontal retorts. Cadmium is volatilized in both the 
roasting and sintering operations and is collected as 
residue (from roasting) and fume (from sintering) 



24 



Coke 





Zinc concentrate 


(Optional) 








Gas to 
atmosphere 




Roaster 


Otfgas dust 
removal system 




Sulfuric acid 
plant 


T 


e 




■ 








Su 


furic acid 












Sinter 
machine 


Offgas dust 
removal system 


To cadmium 
leach plant 




i 










■» Residue 


I 
* 










Electrothermic 
furnance 


Zinc oxide 
furnance 




Oxide recovery 
and packing plant 




Zinc vapor ! ' — 
i 






X 






Condenser 


Fractional 
distillation 


to market 










* 


* 


-*• Dross 

KEY 




Zinc 

casting 


Zinc 
casting 




















1 

+ 
Slab zinc 
to market 


1 

♦ 

Special high-grade 
zinc to market 


Gas 



Figure 11. — Simplified schematic of an electrothermic zinc plant. 



for further processing and recovery. The retorts are 
manually filled with sinter mixed with pulverized coal 
and charged in a batch process to volatilize the zinc. 
The zinc in the charge is reduced and distilled in the 
gas-fired furnaces, and the distilled zinc is collected in 
condensers and cast into slabs of prime western zinc, 
which can be further refined in a distillation process to 
produce a special high-grade product (99.99 pet zinc) 
for market. Only two horizontal retort plants are still 
in operation in market economy countries, both of 
them in Mexico. 



leading from an upper extension of the retort and are 
drawn into a zinc vapor condenser from which the 
liquid zinc is withdrawn for casting as prime western 
zinc or further refined to 99.99+ pet purity. A simpli- 
fied flowsheet for the process is illustrated in figure 12. 
The United States has one vertical retort plant at 
Palmerton, PA, that is currently closed and not ex- 
pected to reopen. Two other plants are still operating 
in market economy countries, one at Anby, France, 
and the other at Miike, Japan. 



Vertical Retort 



Zinc concentrate 



Zinc concentrate 



Vertical retort plants have faced a decline in use 
similar to the horizontal retort plants and for similar 
reasons. Production capacity as a percentage of total 
market economy country capacity has dropped from 
14 pet to 2 pet between 1968 and 1981 (table 21). 
Initial development of both the horizontal and vertical 
retort processes revolved around the availability of a 
cheap supply of natural gas. 

Modern vertical retorts were developed as a modi- 
fication of horizontal retorts with the vertical retort 
configuration having the advantages of continuous, 
mechanized operation giving higher production capa- 
city at a lower unit cost than the batch-type process of 
the horizontal retort. The feed preparation for the 
vertical retort is similar to that of the horizontal 
retort except that the smelting charge is supplied in 
the form of briquettes. The briquettes, made from a 
sinter, bituminous coal, anthracite fines, and clay 
mixture, are first processed in a coking furnace for 
strengthening. They can then withstand handling and 
introduction into the vertical retort without disinte- 
grating. The vertical retort operates on a continuous 
basis with the introduction of new briquettes into the 
charge column to replace the reduced briquettes that 
are continuously withdrawn from the bottom of the 
retort. The zinc vapor and reaction gases produced 
flow upward through the retort and escape via a duct 



Roaster 



Coal 



Briquette 
press 



Coker 



Vertical 
retort 



Zinc vapor 



Splash 
condenser 



Holding 
furnance 



Zinc 
casting 



Slab zinc 
to market 



Sinter 
machine 



Offgas dust 
removal system 



~- Residue 



Sulfuric acid 
plant 



Fractional 
distillation 



Zinc 

casting 



Gas to 

atmosphere 



Sulfuric acid 

to market 



KEY 

Solid 

— Liquid 
Gas 



-» Dross 



Special high-grade 
zinc to market 



Figure 12. — Simplified schematic of a vertical retort zinc 
plant. 



25 



OPERATING COSTS 



Operating costs for mining, beneficiating. trans- 
portation, and smelting-refming were estimated for 
each mine or deposit. Where possible, actual operating 
costs were collected from published sources or contacts 
with company personnel. When actual costs were not 
available, costs were either estimated using standard- 
ized costing techniques or derived from the Bureau's 
cost estimating system (CES) (2). 

The average total cost calculated for each of the 
mines and deposits investigated covers mining, bene- 
ficiation, transportation, smelting-refining, capital re- 
covery, taxes, and profit. These costs often vary great- 
ly depending on such factors as size of the operation, 
mining method, deposit location, stripping ratio, depth 
of the ore body, mill feed grades, complexity of mill 
feed, processing losses, energy and labor rates, pro- 
ductivity, and country and local tax structures. 

The operating costs presented in this section are 
weighted averages on a per-metric-ton-of-ore basis for 
mine and mill operating costs and per-metric-ton-of- 
concentrate basis for transportation costs and 
smelting-refining treatment charges. 



MINE AND MILL 

Weighted-average surface and underground 
operating costs, by country, for producing and un- 
developed lead and zinc deposits are presented in this 
section. Costs for some countries have been aggregated 
to avoid disclosing individual deposit data. Costs are 
shown in dollars per metric ton of ore for mining and 
milling, and per pound of recoverable metal for each 
stage of production. 

Lead Mines and Deposits 

The operating costs for the 22 producing lead 
mines included in table 23 averaged $12.00 per metric 
ton of ore for mining and $5.40 for milling. Mine 
operating costs in the United States averaged about 
one-half the cost of mining in foreign countries, 



primarily because the Missouri room-and-pillar mines 
are highly mechanized, low-cost producers. Mill operat- 
ing costs for U.S. lead mines are lower than foreign 
costs (averaging $5.20 per metric ton of ore com- 
pared with $6.30). because of the simple nature of 
domestic ores which require less processing. For the 
same reasons mentioned for producing mines, the five 
undeveloped deposits in the United States have an 
average mine operating cost approximately one-half 
that of the three undeveloped foreign deposits. Mill 
operating costs would average almost the same for 
foreign and domestic undeveloped deposits. Average 
lead ore grades for producing domestic and foreign 
mines are nearly equal, but grades for undeveloped 
domestic deposits average 70 pet higher than those of 
foreign deposits. 

Zinc Mines and Deposits 

The operating costs for the 109 producing zinc 
mines included in table 24 averaged $17.10 for mining 
and $8.20 for milling. Mine operating costs in the 
United States averaged about 80 pet of the cost of 
mining in foreign countries (although Spain averaged 
only 40 pet of the U.S. mining cost because most of 
the capacity was from low-cost surface mines), pri- 
marily because of the Tennessee room-and-pillar 
mines, which are highly mechanized, low-cost pro- 
ducers. The average United States mill operating cost 
is 35 pet lower than that for foreign producers ($5.50 
versus $8.50), because of the simple mineralogy of the 
Tennessee mine ores, which require less processing. 

The 77 undeveloped zinc deposits have an esti- 
mated average mine operating cost of $13.80 and a 
mill operating cost of $6.00 per metric ton of ore. 
U.S. undeveloped deposit mining operating costs are 
estimated to be 30 pet less than foreign costs (averag- 
ing $11.20 compared with $16.20 per metric ton ore), 
because of the high degree of mechanization and 
productivity inherent in the Tennessee room-and-pillar 
operations. Mill operating costs do not vary significant- 
ly between U.S. and foreign deposits. 



Table 23.— Estimated mine and mill operating costs for producing and undeveloped lead mines and deposits 



PlfOduc "5 es 
Foreign countries 
United Stales 
Total or average 
Undeveloped deposits 
Foreign countries 
United States 
Total or average 



Mines- 


Recoverable 
ore.' 10 3 t 


Average ore grade 


Production potential 3 


Operating cost per 


deposits 


Zinc. Lead, Silver, 
pet pet 2 g t 


Zinc. Lead, Silver, 
10 3 t 10 3 1 10 3 troz 


metric ton 




Mine Mill Total 



13 
9 


116,288 
295,690 


1 75 
1 06 


5 86 
572 


640 
'234 


1.375 
2,208 


6,005 
16,105 


203,970 
191,384 


$18.30 
9.80 


$6 30 
5.20 


$24.60 
1 5 00 


22 


411,978 


1 26 


576 


348 


3,583 


22,110 


395,354 


12.00 


5.40 


1/ -10 


3 
5 


92.301 
41.418 


73 
87 


2.85 
487 


292 
5 6 1 


438 
247 


2,168 
1.928 


64,834 
7,282 


18.20 
970 


6.40 
6.30 


24 60 
16.00 



6 



133.719 



77 



348 



22 1 



6 684 



4,096 



72,116 15.50 6 30 2180 



' Includes mining recovery and dilution 

2 To convert from grams per metric ton to — troy ounces per short ton. multiply by 0291667; troy ounces per metric ton, multiply by 0321507 

1 Includes alt mm, smelter and refinery recoveries over the life of the property 

4 Silver grades for Missouri mines average 1 1 g i 

5 3 of the 4 M«soun lead-zinc properties have no reported recoverable silver 
• Data do not add to total shown because of independent rounding 



26 



Mines- 
deposits 


Recoverable 
ore, 1 I0 3 t 


Average ore grade 

Zinc, Lead, Silver, 
pet pet 2 g/t 


Production potential 3 

Zinc, Lead, Silver, 
10 3 t 10 3 t 10 3 troz 


Operating cost per 
metric ton 




Mine Mill Total 



Table 24. — Estimated mine and mill operating costs for producing and undeveloped zinc mines and deposits 

Producing mines' 

Australia 7 111.200 8.56 6.23 116.6 7,417 5,879 360.192 $23.20 $6.10 $29.30 

Canada 13 350,500 6.29 2.90 54.7 17,129 7,746 476,626 15.80 9.90 25.70 

Germany. Fed. Rep. Of .. . 3 25,000 8.45 2.27 29.0 1,862 405 17,750 25 40 12.10 37.50 

Italy 4 30,200 4.16 1.31 13.7 927 312 11,203 15.00 5.60 20.60 

Japan 8 62,600 4.21 .74 38.3 2,313 361 55,945 21 .20 7.80 29.00 

Mexico 15 140.200 4.63 1.82 139.1 4,947 2,132 508,117 20.90 7.00 27.90 

Peru 14 100,400 6.78 2.77 108.1 5,347 1,971 252,150 23.20 10.80 34.00 

Spain 4 119,400 2.46 .99 27.9 2,204 787 20,250 5.60 9.00 14.60 

Other 25 335,600 5.88 1.28 30.0 15,558 4,072 336,015 17.20 7.80 25.00 

Total or average . 

United States 

Total or average 

Undeveloped deposits: 

Australia 293,700 9.31 4.53 65.7 15,772 7,585 373,928 13.90 4.60 18.50 

Canada 20 261,800 6.32 1.99 44.0 13,118 4,108 268,520 21.40 7.60 29.00 

India 3 71,500 4.51 2.07 16.7 2,171 1,001 28,282 24.50 7.10 31.60 

Ireland 3 25,000 5.63 1.16 1,179 226 23.60 9.30 32.90 

Other 8 305,200 4JH3 .86 35.7 10,876 1,587 240,222 11.50 6.50 18.00 

Total or average 39 957,200 6.37 2.39 44.8 "43.117 14,507 910,952 16.20 6.30 22.50 

United States 38 880,200 4^63 .69 16.9 o6,139 5,441 328,658 11.20 5.70 16.90 

Total or awage 77 1,837,400 5.53 1.58 31.1 "79,255 19,947 1,239,610 13.80 6.00 19.80 

1 Includes mining recovery and dilution. 

2 To convert from grams per metric ton to — troy ounces per short ton. multiply by 0.0291667; troy ounces per metric ton, multiply by 0.0321507 

3 Includes all mill, smelter, and refinery recoveries over the life of the property. 

4 Data do not add to total shown because of independent rounding. 



93 
16 


1,275,100 
144,300 


5.77 
3.28 


2.35 

.14 


64.8 
2.7 


"57,703 
4,140 


23,665 
169 


2,038,255 
10,210 


17.40 
14.40 


8.50 
5.50 


25.90 
19.90 


109 


1,419,300 


5.52 


2.12 


58.5 


"61,842 


23,834 


2,048,465 


17.10 


8.20 


25.30 






SMELTING AND REFINING 

For the purpose of this investigation, all mineral 
concentrates were treated as if they were shipped to 
custom smelters-refineries. The cost of smelting and 
refining includes the treatment charge for processing 
the concentrates and various deductions and pay-fors 
on the metal content of the concentrates. Typical treat- 
ment charges, deductions, and pay-fors are listed in 
table 25 for various concentrates processed by the 
operations evaluated in this investigation. 

To determine typical revenues resulting from a 
concentrate, the grade deduction is first subtracted 
from the concentrate grade and the result is multiplied 
by the pay-f or percent in decimal form. The resulting 



quantity is what the smelter will pay for at the current 
market price minus the price deduction. The price 
deduction covers any further cost to refine the com- 
modity to a finished product. In the case of lead and 
copper, the price deduction (normally $0.07 to $0.10 
per pound), is incorporated as part of the treatment 
charge. 

Treatment charges and smelter schedules vary 
significantly from region to region and sometimes 
from country to country. For example, $150 per metric 
ton was used as the charge for treating lead and zinc 
concentrates in Japan while in Europe, charges as 
high as $200 to $220 per metric ton were used for 
treating lead concentrate and $180 to $200 for zinc 
concentrate. 



Table 25. — Typical smelter schedules 



Commodity 


Grade 

deduction 


Percent 
paid for 


Price 
deduction 


Commodity G^e Percent Price 
deduction paid for deduction 


ZINC, 


AV TREATMENT CHARGE- 


-$184/t CONCENTRATE 


COPPER, AV TREATMENT CHARGE— $130/t CONCENTRATE 2 


Zinc 

Cadmium 




. None 

. .0.2 units ' 

. 0.02 oz 


85 
60 
75 
70 
50 


None 
$1 ,00/lb 
$5.00/oz. 
$0.20/oz. 
None 


Copper 1 unit 100 None 

Gold 0.02 oz 95 $5.00/oz. 


Gold 


Silver 1 oz 95 $0.20/oz. 


Silver 

Lead 


. . 3 oz 

3 units 


BULK LEAD-ZINC, 3 AV TREATMENT CHARGE, $210/t CONCENTRATE 


LEAD, 


AV TREATMENT CHARGE- 


-$176/t CONCENTRATE 2 


Lead None 85 None. 

Zinc do 75 Do. 


Lead . . 




. . 1 .5 units 


95 
95 
95 
60- 


None 
$5.00/oz. 
$0.20/oz. 
$0.40/lb. 


Silver 1 oz 85 Do. 


Gold 


. . 0.02 oz 

. . 1 oz 


Gold 0.02 oz 85 Do. 


Silver 

Copper 


TIN (75 pet), AV TREATMENT CHARGE, $635/t CONCENTRATE 




Tin .1 unit" 100 None. 







' A unit equals 1 .0 pet or 22.05 lb 

2 Treatment charge includes refining charge 

3 Imperial smelting -furnace feed. 



" For every 0.1 pet tin above or below 75 pet, the unit deduction shall be 
decreased or increased by 0.01 unit, respectively. 






27 



TOTAL PRODUCTION COSTS 



Total production costs were determined for the 
216 lead and zinc mines in market economy countries 
and are presented in tables in this section. Mines and 
deposits having combined surface and underground 
operations and primary copper operations containing 
lead and zinc as coproduct or byproduct commodities 
were not included. Costs are presented on a dollar-per- 
pound-metal basis and include mine, mill, smelting- 
refining. other, transportation, and total operating 
costs as well as taxes, byproduct credits, net cost, and 
total cost. 

Smelting-refining includes processing costs for the 
primary commodity while other costs include smelting- 
refining for coproduct and byproduct commodities. 
Transportation includes transportation costs of all 
concentrates to the smelter-refinery. Total operating 
cost is the total of all direct costs before taxes and 
byproduct credits. The taxes category includes all 
property, severance. State, and Federal taxes. Reve- 
nues from coproduct and byproduct commodities have 
also been computed and subtracted from total operat- 
ing cost to arrive at net cost. 

Net cost is the average out-of-pocket cost includ- 
ing all operating charges required to produce refined 
lead or zinc and any credit for byproduct production, 
but does not include recovery of capital or profit. It 
reflects the average lead or zinc price at which the 
mines in the country could break even by covering all 
production costs. A company may be willing to operate 
at this price temporarily if it believes the situation 
will improve in the near future. However, if the com- 
pany's outlook is bleak, it may temporarily shut down 
or permanently close the mine and shift its investment 
to a more profitable venture. An exception is State- 
owned or State-controlled mines, which may continue 
to produce at or belcw this price if the resulting losses 
are less than those incurred if the mine were closed. 
(If the mine were closed, the government may have to 
pay unemployment and other welfare benefits.) Gov- 
ernments also may need the foreign exchange revenues 
generated by the mine to import other materials 
needed in their country. 



The difference between the net cost and the total 
cost is that total cost includes recovery of capital and 
a profit on all investments at a 15-pct DCFROR. For 
some countries, only a small difference exists since 
most of the mines have been producing for many years 
and a large portion of the capital has been written off. 
For other countries, the difference is significant since 
new mines have recently begun production and large 
amounts of capita! have yet to be written off. 



LEAD 

Table 26 compares weighted-average production 
costs per pound lead for producing and undeveloped 
deposits in the United States and foreign countries. 
Costs for producing mines in the United States are 
comparable to foreign costs except that mining costs 
and byproduct credits are lower. Mine operating costs 
average $0.10 per pound lead in the United States 
compared with $0.17 for foreign countries because of 
the low cost, highly productive room-and-pillar mining 
methods used in the Missouri lerfd mines. However, 
foreign mines recover this U.S. cost advantage in by- 
product credits, which average twice those of domestic 
mines. As a result, net and total costs for U.S. and 
foreign mines are nearly equal. 

Operating costs for undeveloped deposits in the 
United States would average slightly higher than 
producing mines, with a total operating cost before 
taxes and byproduct credit only $0.04 higher per pound 
of lead. However, higher capital investments and lower 
byproduct credits result in a much higher total cost of 
$0.50 per pound versus $0.27 for producing mines. 
Taxes for undeveloped domestic deposits are higher 
than those for producing mines ($0.08 per pound 
compared with $0.03) because higher incomes are 
required to provide the stipulated 15 pet DCFROR; 
thus, aggregate tax payments are generally higher 
than for producing operations. 

Foreign undeveloped lead deposits have high 
operating costs mainly because of the high costs of 



Table 26. — Estimated total production costs for producing and undeveloped lead mines and deposits, January 1981 dollars per 

pound of lead recovered 



Mines- 
deposits 



Operating costs 



Mine 



Mill 



Smelting- 
refining' 



Other 2 Transport 3 Total 



Taxes" 



Byproduct 
credit 



Net 
cost 



Total 
cost 



D 'c<; J ; ng - net 
Foreign 
United States 
Total or average 
Undeveloped deposits 
Fofe>gn 
United States 
Total or average 



13 
9 


SO .17 
10 


SO 06 
06 


$0 14 

11 


$0 05 
03 


$0 04 
03 


5 $0.45 
5 34 


$0.04 
.03 


$0.26 
.13 


$0 23 
24 


$0.30 
.27 


22 


12 


06 


12 


04 


04 


38 


03 


.17 


.24 


.28 


3 

5 


36 
12 


13 
08 


15 
11 


08 
04 


11 
03 


' 82 
.38 


.28 
.08 


39 
.12 


5 .72 
.34 


1 20 
.50 


8 


26 


11 


13 


06 


08 


64 


20 


.28 


56 


.87 



' Smelting and refining of lead only 

2 Smelting and refining of all byproduct commodities 

3 Total transportation cost for all concentrates from mill lo smeller and refinery 

4 Includes all pfopenry. Slate Federal, and severance taxes plus any royalty Undeveloped deposits would require higher income in order to provide the 
stipulated 15 pet DCFROFt thus, estimated aggregate tax payments are generally higher for undeveloped deposits 

5 Data do not equal total shown because of independent rounding 



28 



the Black Mountain lead-zinc-silver deposit in the 
Republic of South Africa. The deposit is a large- 
tonnage, low-grade deposit proposed for sequential 
development following depletion of reserves at the 
Broken Hill Mine. High operating costs, taxes, and a 
high capital investment (approximately $500 million) 
result in an average total cost of $1.20 per pound of 
lead for the three foreign deposits (average total 
costs without the Black Mountain deposit would drop 
to $0.55). It should be kept in mind that in many 
countries, special tax incentives and tax holidays can 
effectively reduce the tax burden and, consequently, 
lower the total costs determined for this study. 



ZINC 

Table 27 shows estimated total production costs 
per pound of zinc for producing and undeveloped zinc 
deposits. Mine operating costs for producing mines 
range from a low of $0.15 per pound in Spanish mines 
to a high of $0.31 in Mexican mines. The higher cost 
of underground mining in Mexico and Japan is due to 
the complex nature of the deposits and small capacity 
of many of the mines. As discussed earlier, the mining 
cost per metric ton of ore is lower in the United States 
than in foreign countries. However, owing to the lower 
grade of domestic deposits (3.28 pet zinc, compared 
with 5.77 pet in foreign countries) costs on a per- 
pound basis are higher. 

Mill operating costs range from a high of $0.25 
per pound in Spain to a low of $0.05 per pound in 
Australia. Although U.S. mines had a $3 advantage 
over foreign mines on a per-metric-ton-ore basis (table 



24), this advantage is offset by the lower grade of 
domestic mines. On a per-pound basis, U.S. and foreign 
mines are equal, at $0.10. 

The average cost to refine zinc ranges from $0.15 
to $0.21 per pound of zinc. Japan is represented at the 
low end of this range as a result of a price support 
system whereby smelters can offer low terms on 
custom concentrate contracts because they are guaran- 
teed a price that is higher than the London Metal 
Exchange (LME) price for product sold to domestic 
manufacturers. U.S. refining costs average $0.20 per 
pound, $0.02 greater than foreign zinc refining costs. 

Other costs, including smelting and refining of 
lead and other byproduct commodities, range from 
$0.04 to $0.16 per pound of zinc. This wide range is 
due mainly to differences in byproduct grades, which 
result in additional smelting and refining charges. The 
mines with high costs in this category usually recover 
the added cost in the form of byproduct credits. 

Total operating costs before taxes and byproduct 
credits average $0.61 for producing mines. Mexico has 
the highest operating cost primarily due to high min- 
ing costs. However, this high cost is more than com- 
pensated for by high byproduct revenues ($0.77 per 
pound of zinc, principally from silver), which provide 
Mexico with the lowest net and total cost of any coun- 
try. High operating costs in Australia and Peru are 
also offset by high byproduct credits. Byproduct 
credits for foreign mines average $0.14 per pound 
greater than for U.S. mines. Net cost for producing 
mines averages $0.29 per pound, $0.46 in the United 
States and $0.28 in foreign countries, a difference of 
$0.18 per pound. As a result, U.S. mines have a long- 
run weighted-average total cost estimated at $0.58 per 



Table 27. — Estimated total production costs for producing and undeveloped zinc mines and deposits, January 1981 dollars per 

pound of zinc recovered 



Mines- 
deposits 



Operating costs 



Mine 



Mill 



Smelting- 
retining 1 



Taxes 4 



Other 2 Transport 3 Total 



Byproduct 
credit 



Net 
cost 



Total 
cost 



Producing mines: 

Australia 

Canada 

Germany, Fed. Rep. of 

Italy 

Japan 

Mexico 

Peru 

Spain 

Other 



Total or average 
United States 



Total or average 
Undeveloped deposits: 

Australia 

Canada 

India 

Ireland 

Other 



Total or average 
United States 



Total or average 



7 


$0.18 


$0.05 $0 


19 


$0.16 


$0.03 


$061 


$0.08 


$0.56 


$0.13 


$0.20 


13 


.16 


.10 


18 


.11 


.06 


.61 


.02 


.32 


.31 


.36 


3 


.17 


.08 


15 


.04 


.01 


5 .46 


.02 


.26 


.22 


.24 


4 


26 


.10 


21 


05 


01 


.63 


.02 


.21 


.44 


.50 


8 


.29 


.11 


15 


04 


.01 


5 .59 


.01 


.20 


5 .41 


.44 


15 


.31 


.10 


20 


.11 


.04 


5 .75 


.10 


.77 


5 .09 


16 


14 


.22 


.10 


17 


06 


.05 


5 .59 


.06 


.36 


5 .30 


.35 


4 


.15 


25 


17 


09 


.03 


.69 


.01 


30 


.40 


.51 


25 


.20 


.09 


19 


.07 


.02 


5 .56 


.05 


.29 


.32 


.37 


93 


.20 


.10 


18 


.10 


.04 


5 .61 


.05 


.37 


5 .28 


.33 


16 


.26 


.10 


20 


.07 


.02 


.65 


.04 


.23 


.46 


.58 


109 


.20 


.10 


18 


.09 


.04 


.61 


.04 


.36 


.29 


.35 


5 


.13 


.04 


19 


.12 


.05 


.53 


.15 


26 


5 .41 


.61 


20 


.21 


.08 


17 


.07 


.11 


.64 


.13 


.27 


.50 


.72 


3 


.40 


.12 


19 


08 


.03 


5 .81 


.10 


.26 


5 .66 


.82 


3 


.25 


.10 


20 


.04 


.03 


62 


.19 


.07 


.74 


1.02 


8 


.17 


.09 


18 


.03 


.05 


52 


.08 


.18 


5 .43 


.59 


39 


.18 


.07 


18 


.08 


.07 


58 


.13 


.24 


5 .46 


.66 


38 


.16 


.08 


18 


.03 


.06 


5 .50 


.18 


16 


5 .53 


.86 


77 


.17 


.07 


18 


.06 


.06 


5 .55 


.15 


.20 


5 .49 


.74 



' Refining of zinc only. 

2 Smelting and refining of all byproduct commodities. 

3 Total transportation cost for all concentrates from mill to smelter and refinery. 

4 Includes all property, State, Federal, and severance taxes, plus any royalty. Undeveloped deposits would require higher income in order to provide the 
stipulated 15 pet DCFROR, thus, estimated aggregate tax payments are generally higher for undeveloped deposits. 

5 Data do not equal total shown because of independent rounding. 



29 



pound. SO. 17 above the January 1981 LME price of 
zinc. Italy. Spain, and Japan also have average total 
costs higher than the January 1981 price. 

For most undeveloped deposits zinc could not be 
produced at a low enough cost to earn a 15-pct DCF- 
ROR. The total costs for these deposits average $0.74 
per pound of zinc, more than double those of producing 
mines. Although mining and milling costs for un- 
developed deposits would be slightly less than for 
producing mines, this advantage would be lost in much 



lower byproduct credits (averaging $0.16 per pound 
less) and much higher capital costs. U.S. deposits, 
owing to lower ore grades, would average $0.86 per 
pound, $0.20 greater than foreign deposits. Taxes for 
undeveloped deposits would be greater than those for 
producing mines because higher incomes would be re- 
quired to provide a 15-pct DCFROR; thus, aggregate 
tax payments are generally higher than for producing 
operations. 



CAPITAL COSTS 



Capital costs reflect the total investment required 
for those deposits not producing at the time of the 
study to develop the mine, construct all facilities, and 
begin production. Capital costs for producing mines 
are not shown because some of the mines have been 
producing for many years and a large portion of the 
initial investment has been depreciated. 

Capital costs for exploration, acquisition, develop- 
ment, mine and mill plant and equipment, and infra- 
structure have been calculated for all deposits. For 
most deposits, capital costs for smelting and refining 
are included in the custom operating cost; these costs 
are not discussed in this section. Capital costs for 
developing and explored deposits, by type and size of 
operation, are shown in table 28. All costs are adjusted 
to January 1981 dollars and converted to dollars per 
annual metric ton of ore. The costs shown are averages 
for the deposits by size of operation; actual deposit 
costs may vary greatly depending on deposit location, 
characteristics of the ore body, and other factors. 

Capital costs were analyzed for 12 undeveloped 
surface deposits which have a weighted-average an- 
nual capacity of 1.9 million t of ore. The four deposits 
analyzed with annual ore capacities between 500,000 
and 1 million t have a very high cost of $221 per 
annual metric ton of ore capacity because of the large 
capital requirements for developing three of the 
properties, which are in Alaska. A more reasonable 
total cost for less remote deposits of this capacity 
range would be $85 per annual metric ton of ore. 

Capital costs for surface operations with less than 
500.000 t annual ore capacity would average $35 
million; 500,000- to 1-million-t/yr capacity — $67 mil- 
lion (revised down from the high of $177 million in 



Table 28. — Capital costs of undeveloped lead and zinc deposits, 
January 1981 dollars per annual metric ton of ore 



Ore caDacitv Av ore Ex P l ° r a ,i ° n . 

^ Q s '" Deposits capacity, 10 6 acquisition 

Surface: 

•05 4 

0.5 to 1.0 4 

1.0 to 2.0 1 

>2.0 3 

Total or av. 
Underground 

• 0.5 

0.5 to 1.0. 

1.0 to 2.0. . 
■2 

Total or av 78 .8 30 



Plant and 
equipment 



Intra- 
struc- Total 



t/yr 


development 


Mine 


Mill 


ture 




0.3 


$56 


$21 


$29 


$11 


$117 


0.8 


50 


42 


61 


68 


221 


1.7 


28 


11 


29 


11 


79 


5.5 


4 


16 


19 


11 


50 



12 


1.9 


14 


19 


25 


18 


76 


35 


.3 


35 


34 


35 


13 


117 


31 


.7 


29 


30 


30 


9 


98 


6 


1.4 


35 


27 


27 


83 


172 


6 


3.1 


24 


20 


42 


l I 


97 



27 35 21 113 



Alaska) ; 1 to 2 million — $134 million; and $275 mil- 
lion for deposits with annual capacity greater than 2 
million t. 

Capital costs were also estimated for 78 unde- 
veloped underground deposits. High total capital cost 
per annual metric ton of ore for the 1- to 2-million- 
t/yr capacity range is a result of the remote location 
of many of the deposits, which would result in very 
high infrastructure costs. A more reasonable estimate 
of capital cost per annual metric ton ore capacity for 
this range would be $95 as opposed to $172. Average 
capital cost for underground operations with less than 
500,000 t/yr ore capacity is $35 million; 500,000 to 1 
million— $69 million; 1 to 2 million — $133 million; 
and for annual capacity greater than 2 million t, $300 
million. 



30 



AVAILABILITY OF LEAD AND ZINC 



An economic evaluation was performed on each of 
the studied mines and deposits to determine the aver- 
age total cost of production over its entire producing 
life. The evaluation uses DCFROR techniques to de- 
termine the constant dollar long-run price of the 
operation's primary commodity so that total revenues 
(from the primary commodity and byproducts) are 
sufficient to cover all costs of production, discounted 
at a prespecified rate of return on all investments. An 
implicit assumption in each evaluation is that each 
deposit represents a separate corporate entity. The 
life of each property was determined by assuming that 
the property would operate at 100 pet of mine capa- 
city. The mine life covers only the demonstrated re- 
source level. 

All capital investments incurred 15 or more years 
before the cost date of the analysis (January 1981) 
are treated as sunk costs. Investments incurred dur- 
ing the prior 15 yr have the undepreciated balances 
entered as a capital investment in 1981. All subsequent 
investments, reinvestments, operating costs, and 
transportation costs are expressed in constant January 
1981 dollars. Investment and operating schedules are 
determined as much as possible from published data 
or plans announced by the companies involved. For 
those deposits that have been explored, but where no 
plans to initiate production have been announced, a 
development plan was assumed. The preproduction 
period for these explored deposits allows for only the 
minimum engineering and development time necessary 
to initiate production. Additional time lags and poten- 
tial costs involved in filing environmental impact 
statements, receiving required permits, arranging fi- 
nancing, etc., are not accounted for in the analysis, 
but may be significant in the developed countries. 

The potential tonnage and the average total cost 
determined over the life of the operation for each of 
the mines and deposits evaluated in this study have 
been aggregated onto availability curves that illustrate 
the potential availability of the studied commodity at 
different cost levels. Availability curves are con- 
structed as aggregations of the total amount of the 
studied commodity potentially available from each of 
the evaluated mines and deposits, ordered from those 
having the lowest average total cost to those having 
the highest. The total potential availability of the 
commodity can be seen by comparing a projected 
constant-dollar long-run market price to the average 
total cost values shown on the availability curves. 

Availability curves were developed for 186 mines 
and deposits that were evaluated as operations with 
zinc as the primary commodity, 30 mines and deposits 
that were evaluated as operations with lead as the 
primary commodity, and 19 mines and deposits that 
were evaluated as copper operations with lead and zinc 
as significant byproducts. The .assignment of a par- 
ticular commodity as the primary product, generally 
based on that product providing the largest proportion 
of sales revenue at current market prices, is a neces- 
sary requirement of the evaluation process using a 
price determination model. In reality, owing to the 
complexity of lead-zinc ores, lead and zinc are often 



coproducts. In the case of a number of mines in Mexico 
and Peru, lead and zinc are byproducts of silver pro- 
duction. Moreover, the relationship between individual 
mineral commodities as coproducts and byproducts is 
dynamic, and can change as metal prices fluctuate in 
the marketplace. 

In cases where revenues from byproducts are able 
to cover total production costs (which are burdened 
against the primary product in the analysis), the 
curve will show the total cost of producing the primary 
product to be zero. This situation exemplifies the 
complexity of lead and zinc ores and underscores the 
effect that byproduct values (particularly silver) can 
have on the profitability of a mining operation. 

LEAD 

The 30 mines and deposits evaluated as primary 
lead operations in 10 market economy countries have 
an in situ demonstrated resource of 540.9 million t of 
ore, containing 26.2 million t of recoverable lead. Total 
availability curves illustrating potential availability 
of lead from primary lead mines and deposits in all 
market economy countries and the United States are 
shown in figure 13. The United States contains the 
largest recoverable lead resource, 18 million t (17.35 
million in Missouri), accounting for 68.7 pet of the 



'-KJ 


ll.iliill 




.80 


MARKET ECONOMY COUNTRIES 


- 


70 


- 




60 


J 


- 


50 


J 


- 


40 




- 


.30 


_J ' 


20 

10 


^-^ 


1 i i i i i i i i i 


- 



2 5 5 7,5 10 12 5 15 17 5 20.0 22 5 25.0 



UNITED STATES 



f 



2 5 50 7.5 10.0 12.5 15.0 17.5 20 

TOTAL RECOVERABLE LEAD. 10" t 

Figure 13. — Total recoverable lead from lead mines and 
deposits in market economy countries (including the United 
States) and the United States. 



31 



total, followed by Republic of South Africa with 3.8 
million t (14.5 pet), and Morocco with 1.4 million t 
(.5.3 pet). These three countries account for 88.5 pet 
of the potentially recoverable lead from all of the 
mines and deposits evaluated with lead as the primary 
product. One explored South African deposit, with 
potential total recoverable lead of 1.9 million t at an 
estimated total cost of over SI per pound, is not shown 
on the market economy country curve. 

Approximately 43.8 million t of lead is potentially 
recoverable as a byproduct from mines and deposits 
evaluated as primary zinc operations (fig. 14). The 
largest individual sources of potential lead as a by- 
product of zinc arc Australia with 13.5 million t (30.8 
pcO. Canada with 11.9 million t (27.2 pet), and the. 
United States with 5.6 million t (12.8 pet). Producing 
zinc mines account for 23.8 million t of lead, 54.4 pet 
of the total. Producing U.S. zinc mines account for 
only 169.000 t of lead. 

The 19 mines and deposits that were evaluated as 
primary copper operations can potentially produce 
454.000 t of byproduct lead. The total amount of lead 
potentially recoverable from primary lead deposits, 
and as a byproduct of zinc and copper, is 70.4 million t. 

Total availability curves for all market economy 
countries and the United States, with a comparison of 
potentially recoverable lead from producing mines and 
from undeveloped deposits, are shown in figure 15. 
Of the 26.2 million t of lead estimated to be potentially 
recoverable from the 30 mines and deposits evaluated 
as primary lead operations. 22.1 million t (84.4 pet) is 
from producing mines and 4.1 million t (15.6 pet) is 
from undeveloped deposits. The nine mines in the 
United States account for 72.8 pet (16.1 million t) of 
the total potential tonnage from the producing mines 
evaluated for the study, and have a weighted-average 
total cost of SO. 27. The foreign production weighted- 
average cost is SO. 30. As a result, nearly all produc- 
ing mines in market economy countries are able to 
produce at or under the January 1981 lead price of 
SO. 34 per pound. 

The five undeveloped deposits in the United States 
have an estimated total cost of SO. 50, nearly double 
that of producing U.S. mines. The three non-U. S 




TOTAL RECOVERABLE 

Figure 14. — Total availability of lead as a byproduct of 
primary zinc mines and deposits in market economy coun- 
tries. 



:V 




r l 


i i i i i i i 




8C 




I 


MARKET ECONOMY COUNTRIES 


- 


70 


- 


/ 


eloped deposits 


- 


60 




1 




( 


50 




J 




1 




-- 




Producing mines f 




3C 


,1 ' 


IC 


_j 1 


I 


r 


i i.l 1 1 1 1 





75 






17 5 20.0 22.5 



IC 



UNITED STATES 
lUndeveloped deposits 



60 - , I 



3C - 



Producing mines 



50 • 75 IOO 12.5 

TOTAL RECOVERABLE LEAD. 10" t 



Figure 15. — Total recoverable lead from producing mines 
and undeveloped deposits in market economy countries 
(including the United States) and the United States. 



market economy country deposits costs are much 
higher with an estimated weighted-average total cost 
of $1.20 per pound. This average, however, is biased 
by the one South African deposit which has a total 
cost of well over $1 and is not included in the curve. 
Excluding this one deposit, the cost for the two re- 
maining deposits drops to $0.55 per pound. None of the 
undeveloped deposits has a total cost that is less than 
$0.34 per pound of lead. This indicates that the long- 
run market price for lead will have to rise above the 
current (1981) market level, or that the market prices 
of associated coproducts or byproducts will have to 
increase before any of these deposits could be de- 
veloped on a profitable basis. Technological changes, 
such as the recovery of cobalt and nickel from Mis- 
souri lead ores, enhanced recovery of zinc from lead 
furnace slag, or technological improvements in lead 
smelting to reduce process costs would also alter the 
potential profitability of new projects. 

Potential annual production levels for producing 
lead mines in market economy countries and the 
United States for 1981 to 1995 are shown in figure 16. 
The market economy country curve begins a gradual 
annual production decline in 1989, and begins to 
decline at a faster rate in 1994. Almost all the decline 
is from the potential depletion of non-U. S. mines as 
evidenced by the almost constant curve for the United 
States. However, it is doubtful that the demonstrated 
resource of these producing mines will decline at the 
rate indicated by the curve. Many of the lead mine 
operators in the world report their demonstrated 



32 



T 


i i i i i — 

$060 MARKET ECONOMY 
'-v.. 


- 


\~__^ 


- 


f n -5A 


__ — i 




,.i J.. .._ 1 1. .' 1 



| , 


t T 1 1 "■' 

UNITED STATES 




$035 


" 


$0.30 


- 


- 




$0 25 




$0.20 


1 1 1 1 1 1 



1987 1989 

YEAR 



Figure 16. — Potential annual availability of primary lead 
from producing lead mines in market economy countries 
(including the United States) and the United States, at va- 
rious production costs per pound. 



resources for only a few years ahead of their current 
mining position and increase or maintain their re- 
serves as mining continues. Also, in many cases demon- 
strated resources are increased each year as a result of 
ongoing exploration programs. The demonstrated re- 
source estimates that appear in this report are based 
on 1981 company reported data. However, there is a 
high probability that additional resources exist that 
will allow most of the currently producing mines to 
continue beyond the time frame of reported reserves. 

Similar curves for undeveloped lead deposits are 
shown in figure 17. Because startup dates for many 
undeveloped deposits are not known, construction of 
annual availability curves for them was based on the 
assumption that preproduction would begin in year 
N. For mines that were in the development stage in 
1981, production shows up in the first few years of 
the curve. Potential annual production peaks rapidly 
and then begins to decline (an exception is the U.S. 
curve at a lead price of $0.35 per pound, which remains 
constant) . As mentioned previously, none of the de- 
posits can produce lead at an estimated long-run total 
cost of under $0.34 per pound. One U.S. deposit has 
an estimated long-run total cost of $0.35 per pound, 
but it is the only deposit that approaches the 1981 
market price. Therefore, it is doubtful that more than 
three or four of these deposits will be developed in the 
near future. 



N Year preproduction 
development begins 




-^ \ 



MARKET ECONOMY 
COUNTRIES 



$0 90 

~$a75~ 



$0 55 



$0.35 





r 

/ 
i 

/ 

i 
i 
i 


S 


/ 


0\ 

\ 
N 


UNITED 


STATES 

$0 90 
$0.65 






$0 55 


1 ; 
1 ! 

1 : 

I i 

1 / 

/ / 

1 : 












$0 35 


' -' / 
' '' / 

/ 1 




1 


1 1 




- 



N+l N + 3 N + 5 N+7 N + 9 N + ll N + 13 N + 15 

YEAR 

Figure 17. — Potential annual availability of primary lead 
from undeveloped deposits in market economy countries 
(including the United States) and the United States, at 
various production costs per pound. 

ZINC 

At the demonstrated resource level, approximate- 
ly 141.1 million t of zinc metal is potentially recover- 
able from the 186 mines and deposits evaluated as 
primary zinc operations in 29 market economy coun- 
tries. The United States contains the largest poten- 
tially recoverable resource, 40.3 million t, which ac- 
counts for 28.6 pet of the total, followed by Canada 
with 30.2 million t (21.4 pet), and Australia with 23.2 
million t (16.4). The combined total for these three 
countries amounts to 66.4 pet of the potentially re- 
coverable resource in market economy countries. The 
total availability curves illustrating potential avail- 
ability of zinc from primary zinc mines and deposits 
in all market economy countries, the United States, 
Canada, and Australia are shown in figure 18. Note 
that the highest total zinc production cost on any of 
the curves is $1.50 per pound. Three explored deposits 
(one each in Australia, Canada, and India) with total 
zinc production costs estimated at higher than $1.50 
per pound and a combined potential production of 1.8 
million t, are not shown on the curves. An additional 
4.3 million t of zinc is potentially available from 21 
mines and deposits evaluated as primary lead opera- 
tions, with 58 pet (2.5 million t) of this potential 
tonnage in the United States (fig. 19). 



33 



I 5C 
1.40 
1. 30 
1.20 
1.10 
1.00 
.90 

ec 

.70 

.60 

- 

- 
.10 



MARKET ECONOMY COUNTRIES 



— 








20 30 40 SO 60 70 80 90 IOC 110 I2C I3C 140 

1.40 

1.20 



^ 




..... 








1 


- 


:: 






- 


v 






- 


K 








- 


U. 






-: 


S^ 


. . 1 i I . L. 


:: 


J 



UNITED STATES 



J I I L 



-J I I L 



16 20 24 28 32 36 40 44 



~\ 1 1 — i 1 — i 1 — i r 

CANADA 



4 6 6 



J I I L 



J I I I I 1 I L 



20 22 24 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 

TOTAL RECOVERABLE ZINC. 10 e t 



Figure 18. 
Canada), the 



— Total recoverable zinc from market economy countries (including the United States, Australia, and 
United States, Australia, and Canada. 








Figure 19. — Total availability of zinc as a byproduct of 
primary lead mines and deposits in market economy coun- 
tries (including the United Slates) and the United States. 



As shown in figure 20, another 8.3 million t of zinc 
is potentially recoverable as a byproduct from the 19 
mines and deposits evaluated as primary copper opera- 
tions with Canada accounting for 4.6 million t (55 
pet) of the total; none of this potential tonnage is in 
the United States. The total tonnage of potentially 
recoverable zinc from all three sources (primary zinc, 
primary lead, and primary copper) amounts to 153.7 
million t, with 42.7 million t (27.8 pet of the total) 
from U.S. demonstrated resources. 



& 1 40 

o. 

o. 
o 


I 1 ! 1 1 I I i 

[ 


o 






D 

■ 




Q. 


, — l 


01 


| 


o 


^J 


o 


) 


°. 60 






O 

J 














\ 

■ i i i i i i i 



/I maiii i /ii. 



Figure 20. — Total availability of zinc as a byproduct of 
primary copper mines and deposits in market economy 
countries. 






34 



Total availability curves for all market economy 
countries and the United States, with a comparison of 
tonnage from producing mines and from undeveloped 
deposits (explored deposits and developing mines), are 
shown in figure 21. Of the 141.1 million t of primary 
zinc estimated to be potentially recoverable from 
market economy countries, 43.8 pet (61.8 million t) is 
from producing mines and 56.2 pet (79.3 million t) 
is from undeveloped deposits. The 109 producing 
mines evaluated as primary zinc mines have a 
weighted-average estimated total cost of $0.35 per 
pound of zinc (see table 27). Total potential zinc 
production from these mines amounts to 61.8 million 
t, with 44.3 million t (72.5 pet of the total) potentially 
available at an estimated cost level (including a 15-pct 
DCFROR) below the January 1981 market price of 
$0.41 per pound. Approximately 11 million additional 
metric tons of zinc can potentially be recovered from 
17 producing mines that can produce at a break-even 
cost of $0.41 per pound (meaning that they can cover 
all operating costs and recover capital at a 0-pct 
DCFROR) . This means that 81 of the 109 producing 
zinc mines could potentially break even at January 
1981 estimated costs and prices. Producing mines that 
cannot cover production costs at a zinc price of $0.41 









I I 1 1 I 1 


1.40 






MARKET ECONOMY COUNTRIES J ~ 


1 20 


- 




j 


1.00 






, r 

Undeveloped deposits^ 


.80 


" 




/V 


.60 






_ r r 






, / ~ J 


JProducing mines 


40 


J J 


1 


_ rJ - J -> 


.20 


1 I 1 1 1 ! 



20 30 40 50 60 70 80 



UNITED STATES 




Producing mines j- 

_, 'Undeveloped deposits 



J L 



TOTAL RECOVERABLE ZINC, 1 0» I 



Figure 21. — Total recoverable zinc from producing mines 
and undeveloped deposits in market economy countries 
(including the United States) and the United States. 



per pound may eventually have to be closed if prices 
do not improve (operations in some countries receive 
a subsidy from the government and therefore can con- 
tinue to produce at lower zinc prices). 

A total of 79.3 million t of zinc is potentially 
recoverable from the 77 undeveloped deposits evaluated 
in market economy countries with a weighted-average 
estimated total cost of $0.74 per pound (table 27) . 
Only 1.85 million t (2.3 pet of the total) is estimated 
to be recoverable at a total cost below the January 1981 
market price of $0.41 per pound of zinc. 

The curve for the United States shows that 4.1 
million t of zinc is potentially recoverable from the 15 
zinc mines that were producing in January 1981, which 
is only 10.3 pet of the total U.S. recoverable resource 
of 40.3 million t, and is less than 7 pet of the 61.8 
million t of zinc potentially recoverable from produc- 
ing mines in all market economy countries. The 
weighted-average total cost of production for these 
15 mines is $0.58 per pound of zinc (ranging from 
$0-00 to $0.74) in January 1981 dollars. From demon- 
strated resources in 1981, only 454,000 t of recoverable 
zinc (11 pet of total recoverable zinc from U.S. pro- 
ducers) is potentially recoverable below a long-run 
total cost of $0.41 per pound of zinc. This cost situa- 
tion has likely contributed to the number of zinc 
operations closing or going on a temporary standby 
status during 1981 and 1982. The evaluations for the 
38 undeveloped deposits resulted in potential produc- 
tion of 36.1 million t of zinc with a weighted-average 
total cost of $0.86 per pound of zinc in constant 
January 1981 dollars. This situation would make most 
of these deposits uneconomic under present economic 
conditions. A shift in the price structures of zinc, lead, 
or silver would alter this situation, however. 

Potential annual production levels for producing 
zinc mines in market economy countries and the 
United States for 1981 to 1995 are shown in figure 22. 
As with the curves for lead mines, the curves indicate 
a fairly rapid depletion rate, which is based more on 
the criteria of this study rather than what will prob- 
ably occur. 

Potential annual production levels for undeveloped 
zinc deposits in market economy countries and the 
United States are shown in figure 23. If preproduction 
of all undeveloped deposits were to begin in year N, 
production would peak in the seventh year and remain 
constant through year N + 14. Only three of the un- 
developed deposits evaluated for this study have esti- 
mated total production costs that are less than the 
January 1981 market price ($0.41 per pound) for zinc. 
Actual development of these deposits will depend on 
the level of demand and the associated market prices 
for zinc, lead, silver, copper, gold, and other coproducts 
or byproducts of zinc production. 

The foregoing availability analyses can be con- 
cisely summarized by the use of tables showing poten- 
tial recoverable zinc and lead, by country, with the 
associated weighted-average estimated long-run aver- 
age total costs of production. These data are presented 
in tables 29 through 34. 



35 



* x 

: sr 



; 



MARKET ECONOMY 
COUNTRIES 






$040 



$C20 



2? - .— 



, 1 , 

UNITED STATES 

/ "A v 

\ \ \ 


- 


J" 


— 


$0 45 


- 


"-^^ $0 35 



Figure 22. — Potential annual availability of zinc from pro- 
ducing zinc mines in market economy countries (including 
the United States) and the United States, at various produc- 
tion costs per pound. 



1 1 1- 1 1 

MARKET ECONOMY 

COUNTRIES / 

/ 

N Year preproduction / 
development beqms / 
/ 


l 

_ $1 50 
$0.80 

$060 


- 


'/ ' 


$0.50 


~t*0£ 


$0 40 


""" i i 






N+7 N+9 

YEAR 



N + 13 N + 15 



Figure 23. — Potential annual availability of zinc from un- 
developed deposits in market economy countries (including 
the United States) and the United States, at various produc- 
tion costs per pound. 



Table 29. — Comparison of estimated long-run average total costs of potential zinc metal production from primary zinc mines and 

deposits 



Producing mines Undeveloped deposits 



Potential 

production 

10 3 t 



Cost' 



Potential 

production. 

10 3 t 



Cost' 



Producing mines Undeveloped deposits 



Potential 

production. 

10 3 t 



Cost' 



Potential 

production, 

10 3 t 



Cost' 



Akgena 
Argentina 

Austna 

BoJr/ia 

Braz 

Burma 

Canada 

F "land 

France 

Germany. Fed Rep of 

Greece 

Gree^iano 

Honou'as 

India 

Ireland 



1447 
428 6 

74167 
3180 
148 6 
709 1 
943 
17.128 8 
6667 
349 8 

1 861 6 
6162 
378 6 
404 2 

1 .055 2 

2.540 5 



W 
W 
$0 20 
W 
28 
W 
W 
36 
43 
57 
24 
00 
W 
W 
W 
43 



NAp 

NAp 

15.7722 

NAp 

NAp 

605.3 

NAp 

13.1184 

NAp 

202 1 

NAp 

NAp 

NAp 

NAp 

2.171 

1.1790 



NAp 
NAp 
$0.61 
NAp 
NAp 

W 
NAp 

72 
NAp 

68 
NAp 
NAp 
NAp 
NAp 

82 
1 02 



Italy 

Japan 

Mexico 

Morocco 

Namibia 

Peru 

Portugal 

South Africa. Rep ot 

Spam 

Sweden 

Turkey 

Zaire 

Zambia . . . 



9273 

2.312.9 

4,946.9 

NAp 

2738 
5,346.6 
2,3053 
NAp 
2.2035 
1,697 

1542 
2.9458 

327 8 



$0 50 
.44 
.16 
NAp 
W 
.35 
W 
NAp 
51 
.35 
W 

w 
w 



583 

NAp 

590.9 

759 

NAp 

NAp 

NAp 

7,751.5 

1,592.2 

NAp 

NAp 

NAp 

NAp 



Total or average 
United States 

Grand total or av 



57,702 7 
4,139 7 



58 



43. r ? 8 
36,1385 



61.842 4 



.34 =79,2554 



NAp Not applicable W Withheld, company proprietary data 
' Weighted-average total cost ot production per pound ot zinc 
1 Data do not add to total shown because of independent rounding 



W 

NAp 

W 

W 

NAp 

NAp 

NAp 

W 

$0 82 

NAp 

NAp 

NAp 

NAp 



86 



74 



36 



Table 30. — Comparison of estimated zinc metal production as a byproduct from lead mines and deposits at the estimated long-run 

average total costs of primary lead production 





Producing 


mines 


Undeveloped deposits 




Producing 

Potential 

production, 

10 3 t 


mines 
Cost' 


Undevelope< 

Potential 

production, 

10 3 t 


i deposits 




Potential 

production, 

10 3 t 


Cost' 


Potential 

production, 

10 3 t 


Cost' 


Cost 1 


Australia 

France 


488.5 

31.8 

NAp 

20.6 

42.1 


W 
W 
NAp 
W 
W 


NAp 
NAp 
129.3 
10.5 
NAp 


NAp 

NAp 

W 

W 

NAp 


South Africa, Rep. of 

Sweden 

Total or average 

United States 


628.4 
163.3 


W 
W 


297.7 
NAp 


W 
NAp 


Mexico 

Morocco 


1,374.7 
2,208.2 


$0.28 


437.5 
246.5 


$0.50 


Namibia. 


Grand total or av 


2 3,582.8 


.28 


684.0 








.87 



NAp Not applicable. W Withheld, company proprietary data. 

1 Weighted-average total cost of production per pound of lead. 

2 Data do not add to total shown because of independent rounding. 

Table 31 . — Comparison of estimated zinc metal production as a byproduct from copper mines and 
deposits at the estimated long-run average total costs of primary copper production 





Producing 


mines 


Undeveloped deposits 








Producing 

Potential 

production, 

10 3 t 


mines 
Cost 1 


Undevelopec 

Potential 

production, 

10 3 t 


i deposits 




Potential 

production, 

10 3 t 


Cost 1 


Potential 

production, 

10 3 t 


Cost 1 


Cost 1 


Australia 

Canada 

Finland 

Japan 


616.6 

4,477.6 

35.4 

649.2 

87.0 


W 
$0.25 
.69 
W 
W 


159.1 
81.7 
NAp 
NAp 
NAp 


W 

W 
NAp 
NAp 
NAp 


Peru 

South Africa, Rep. of 

Sweden 

Turkey 

Total or average 


NAp 
131.4 
156.1 

NAp 


NAp 
W 
W 

NAp 


1,267.3 
NAp 
NAp 

6505 


W 

NAp 

NAp 

$1.06 


Norway 


6,153.3 


$0.42 


2 2,158.7 


1.14 



NAp Not applicable. W Withheld, company proprietary data. 

1 Weighted-average total cost of production per pound of zinc. 

2 Data do not add to total shown because of independent rounding. 

Table 32.— Comparison of estimated long-run average total costs of potential lead metal production 

from primary lead mines and deposits 





Producing 


mines 


Undeveloped deposits 




Producing 

Potential 

production, 

10 3 t 


mines 
Cost 1 


Undevelopec 

Potential 

production, 

10 3 t 


deposits 




Potential 

production, 

10 3 t 


Cost 1 


Potential 

production, 

10 3 t 


Cost 1 


Cost 1 


Australia 

Canada 

France 

Mexico 

Morocco 


708.4 

35.8 

170.1 

136.8 

1,281.4 

375.8 


W 
W 
W 

w 

$0.26 
W 


NAp 
NAp 
NAp 
211.3 
82.7 
NAp 


NAp 
NAp 
NAp 
W 
W 
NAp 


South Africa, Rep. of 

Spain 

Sweden 

Total or average 

United States 


1,905.4 

83.5 

. .. 1,307.7 

6,004.9 
. .. 16,104.9 


W 

W 

$0.33 

.27 
.28 


1.874.3 
NAp 
NAp 
2,168.3 
1,927.7 
4,095.9 


W 
NAp 
NAp 

$0 50 


Namibia. 


Grand total or av 


22,109.9 


.87 



NAp Not applicable. W Withheld, company proprietary data. 

1 Weighted-average total cost of production per pound of lead. 

NOTE. — Data do not add to totals shown because of independent rounding. 

Table 33.— Comparison of estimated lead metal production as a byproduct of primary zinc mines 
and deposits at the estimated long-run average total costs of primary zinc production 



Producing mines Undeveloped deposits 



Potential 

production, 

10 3 t 



Cost 1 



Potential 

production, 

10 3 t 



Cost 1 



Algeria 

Argentina 

Australia 

Austria 

Bolivia 

Brazil 

Burma 

Canada 

Finland 

France 

Germany, Fed. Rep. of 

Greece 

Greenland 

Honduras 

India 

Ireland 



35.1 

367.5 

5,878.8 

84.5 

19.0 

NAp 

134.0 

7,745.7 

21.2 

18.0 

404.5 

484.0 

120.8 

223.0 

389.6 

583.1 



W 

W 

W 

W 

$0.28 

NAp 

W 

.36 

W 

.57 

.24 

.00 

W 

W 

W 

.43 



NAp 
NAp 

7,585.0 

NAp 

NAp 

181.1 

NAp 

4,107.7 
NAp 
59.4 
NAp 
NAp 
NAp 
NAp 

1,001.1 
225.8 



NAp 
NAp 
$0.61 
NAp 
NAp 
W 
NAp 

.73 
NAp 

.68 
NAp 
NAp 
NAp 
NAp 

.82 
1.02 



Producing mines Undeveloped deposits 



Potential 

production, 

10 3 t 



Cost 1 



Potential 

production, 

10 3 1 



Cost 1 



Italy 

Japan 

Mexico 

Morocco 

Namibia 

Peru 

Portugal 

South Africa, Rep. of . 

Spain 

Sweden 

Turkey 

Zambia 



311.7 

361.4 

2,132.4 

NAp 

79.0 

1,970.8 

1,014.1 

NAp 

787.5 

336.4 

4.8 

158.4 



$0 50 
.44 
.16 
NAp 
.43 
.35 
W 
NAp 
.50 
.35 
W 
W 



28.2 

NAp 

697.9 

13.9 

NAp 

NAp 

NAp 

434.2 

172.6 

NAp 

NAp 

NAp 



W 

NAp 

W 

W 

NAp 

NAp 

NAp 

W 

W 

NAp 

NAp 

NAp 



Total or average 23,665 3 

United States 168.5 



.44 



14,506.9 
5,440.5 



$0.72 



Grand total or av 2 23,833.7 



.33 



19,947.4 



.68 



NAp Not applicable. W Withheld, company proprietary data. 

1 Weighted-average total cost of production per pound of zinc. 

2 Data do not add to total shown because of independent rounding 



37 



Table 34.— Comparison of estimated lead metal production as a byproduct from copper mines 
and deposits at the estimated long-run average total costs of primary copper production 





Producing 


mines 


Undeveloped deposits 




Producing 

Poti 
produi 

10' t 


mines 
Cost' 




itial 

non, 


deposits 




Pott? 
production, 


Cost' 


Potential 

production, 

10' t 


Cost' 


Cost' 


Austrai;a 
Canada 


198.3 
71.0 


W 
W 


8.5 
NAp 


W 
NAp 


Namibia 
Total or average 


107.6 

685 




W 

w 


NAp 
NAp 


NAp 
NAp 


4454 


$0.38 


85 


W 



NAp Not applicac e v\ Withheld, company proprietary data 
1 Weighted-ave-age total cost of production per pound of copper 



IMPORTANCE OF SILVER AS A BYPRODUCT OF LEAD AND ZINC PRODUCTION 



The most important byproduct associated with 
the production of lead and zinc is silver. The 186 
mines and deposits evaluated as zinc operations con- 
tain approximately 3.3 billion tr oz of recoverable 
silver, and the 30 mines and deposits evaluated as lead 
operations account for 468 million tr oz. The 19 mines 
and deposits evaluated as copper operations with lead 
and zinc as byproducts account for an additional 242 



million tr oz of recoverable silver. Approximately 
two-thirds of total world silver resources are asso- 
ciated with copper, lead, and zinc deposits (11). Re- 
coverable silver as a byproduct of potential leat 
zinc production, by country, is shown in table 35. 

The impact of byproduct silver on the economics 
of lead and zinc availability is illustrated in figures 24 
and 25. Figure 24 shows potential recoverable lead 



Table 35.— Total recoverable silver as a byproduct of potential lead and zinc production, thousand troy ounces 



Producing mines Undeveloped deposits 



Pnmary 

lead 



Primary 
zinc 



Primary 
lead 



Primary 
zinc 



Aae-a NAp 910 

NAp 25.959 

Austrana 37.703 360.192 

Bolivia NAp 16.266 

NAp 9.857 

Ha 120 476,626 

NAp 7,683 

=-a-:e 14 250 8.373 

Germany Fed Rep ot NAp 17.750 

Greece NAp 48.078 

Greenland NAp 2.819 

Honduras NAp 25.447 

India NAp 15.456 

fcnlmicl NAp 10233 

haty . NAp 1 1 .203 

,a=a- NAp 55.945 



NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 



NAp 
NAp 

373.928 
NAp 
NAp 

268.520 
NAp 
8,439 
NAp 
NAp 
NAp 
NAp 
28.282 
NAp 
853 
NAp 



Mexico 
Morocco 
Namibia . 
Peru. 
Portugal 

South Africa, Rep. of . 
Spain. 
Sweden 
Zaire 
Zambia 
Total 
United States 

Grand total 
Total . . 2,443,819 



Producing mines 


Undevelop 


Bd deposits 


Primary 


Primary 


Primary 


Primary 


lead 


zinc 


lead 


zinc 


25,388 


508,117 


15,185 


165,220 


19,081 


NAp 


4,945 


6,310 


14,593 


1,962 


NAp 


NAp 


NAp 


252,150 


NAp 


NAp 


NAp 


109,132 


NAp 


NAp 


82,707 


NAp 


44,704 


37,663 


1,385 


20,250 


NAp 


21,737 


8,741 


39,190 


NAp 


NAp 


NAp 


13.968 


NAp 


NAp 


NAp 


690 


NAp 


NAp 


203,968 


2,038,256 


64,834 


910,952 


191,384 


10,210 


7,282 


328,657 


'395,354 


'2,048,465 


72,116 


'1,239,610 



1,311,726 



NAp Not applicable ' Data do not add to totals shown because of independent rounding 






/r 






, i 



■■■ 



- 5 






_f 






JL 



• 



Figure 24, — Total availability of lead from mines and de- 
posits in market economy countries with byproduct silver 
at varying prices 



— — 1 1 1 1 — 


1 i 

r/lr 






- 








J 


uyj 




-* 


r'i f 




/ 




-J r 






i ' 






Figure 25. — Total availability of zinc from mines and de- 
posits in market economy countries with byproduct silver 
at varying prices. 



38 



from lead mines and deposits in market economy 
countries with different prices for byproduct silver, 
and figure 25 illustrates the effect of different silver 
prices on the availability of zinc from primary zinc 
mines and deposits. These curves were constructed by 
holding all costs and revenues constant except for the 
revenues for byproduct silver at varying prices. It 
should be kept in mind that these are long-run analyses 
and that the silver price variations are long-run prices 
in constant January 1981 dollars, and do not reflect 
short-run fluctuations in the price of silver. In order 
to effect the shifts in the curves shown in figures 24 
and 25, any price change of silver would have to be 
sustained over a number of years. 

The results of the analyses illustrated in the these 
figures are presented in tabular form, in tables 36 and 



37, which show the weighted-average total costs of 
lead and zinc production for producing mines and un- 
developed deposits in market economy countries with 
byproduct silver prices at $5, $20, and $50 per tr oz. 
These weighted-average total costs can be compared 
with the costs presented in tables 29 and 32 which 
were determined with a byproduct silver price of $10 
per troy ounce. It is not surprising that the greatest 
impact of byproduct silver revenues appears in coun- 
tries with the largest silver resources, namely Aus- 
tralia, Mexico, and Peru. This analysis further under- 
scores the competitive advantage enjoyed by the major 
producers of zinc with high byproduct silver content 
compared with most of the U.S. zinc producers in 
Tennessee, which have no byproduct silver at all. 



Table 36. — Weighted-average total cost of production per pound of lead with various prices per troy 

ounce of byproduct silver 

$5 $20 $50 

Producing Undeveloped Producing Undeveloped Producing Undeveloped 
mines deposits mines deposits mines deposits 

Australia W NAp W NAp W NAp 

Canada W NAp W NAp W NAp 

France W NAp WWW NAp 

Mexico W W W W W W 

Morocco $0.29 W $0.22 NAp $0.12 W 

Namibia W NAp WWW NAp 

South Africa, Rep. of W W W NAp W W 

Spain W NAp W NAp W NAp 

Sweden .34 NAp .31 NAp .24 NAp 

United States .28 $0.50 .26 $0.48 .22 $0.46 

Average .31 .91 .24 .80 19 .63 

NAP Not applicable. W Withheld, company proprietary data. 



Table 37.— Weighted-average total cost of production per pound of zinc with various prices per troy 

ounce of byproduct silver 

$5 $20 $50 

Producing Undeveloped Producing Undeveloped Producing Undeveloped 

mines deposits mines deposits mines deposits 

Algeria W NAp W NAp W NAp 

Argentina W NAp W NAp W NAp 

Australia $0.26 $0.65 $0.15 $0.51 $0.06 $0.31 

Austria W NAp W NAp W NAp 

Bolivia .52 NAp .26 NAp .24 NAp 

Brazil W W W W W W 

Burma W NAp W NAp W NAp 

Canada .41 .76 .26 .64 .06 .43 

Finland .45 NAp .38 NAp .24 NAp 

France .60 .77 .50 .49 .30 .01 

Germany, Fed. Rep. of .26 NAp .19 NAp .09 NAp 

Greece .01 NAp .00 NAp .00 NAp 

Greenland W NAp W NAp W NAp 

Honduras W NAp W NAp W NAp 

India W .85 W .76 W .58 

Ireland .43 1.02 .42 1.02 .41 1.02 

Italy .53 W .48 W .48 W 

Japan .48 NAp .36 NAp .22 NAp 

Mexico .37 W .05 W .00 W 

Morocco NAp W NAp W NAp W 

Namibia W NAp W NAp W NAp 

Peru .44 NAp .22 NAp .07 NAp 

Portugal W NAp W NAp W NAp 

South Africa. Rep. of NAp W NAp W NAp W 

Spain .52 W .47 W .36 W 

Sweden .40 NAp .29 NAp .16 NAp 

Turkey W NAp W NAp W NAp 

United Sates .58 .88 .57 .82 56 .72 

Zaire ' W NAp W NAp W NAp 

Zambia W NAfs W NAp W NAp 

Average .40 .78 .27 .69 .16 .56 

NAp Not applicable W Withheld, company proprietary data. 



39 



DEMAND FOR LEAD AND ZINC 



The long-run situation for the lead industry is 
more complicated than that for zinc, since primary 
lead producers not only face stiff competition from 
each other, but from the large and growing secondary 
industry as well. Total world primary lead demand is 
forecast to increase at an annual rate of 2.4 pet per 
year through 2000, with a cumulative primary demand 
of 77 million t over the 20-yr period. Total demand 
for lead, including secondary lead, is forecast to in- 
crease at an annual rate of 2.8 pet (3.2 pet for second- 
ary leadV For the United States, total demand is fore- 
cast to grow at an annual rate of 1.8 pet. with primary 
lead demand increasing at a 1.5-pet annual rate and 
demand for secondary lead growing at an annual rate 
of 2.0 pet. The part of U.S. demand met by secondary 
lead is expected to approach 60 pet by 2000. as opposed 
to slightly over 50 pet at the present time, owing to 
gradual structural and technological changes in the 
industry and a relative increase in nondissipative end 
uses for lead (S). Based on this forecast, cumulative 
demand for primary lead in the United States between 
1981 and 2000 is estimated to be 13.8 million t. 

Current demonstrated resources estimated to be 
recoverable in the United States at long-run produc- 
tion costs under the 1981 market price of $0.34 per 
pound amount to 16.18 million t, which is well above 
the estimated cumulative demand of 13.3 million t. 
Total recoverable resources in market economy coun- 
tries amount to 70.4 million t (41.1 million t poten- 
tially available at 1981 market prices), and cumulative 
demand for primary lead through 2000 (including 
central economy countries) equals 77 million t. As with 
zinc resources, demonstrated resource estimates for 
lead have increased significantly over the past 20 yr. 
The 1962 resource estimate for lead (12) was 45.2 
million t for the total world, with 17 million t in the 
United States. These resources were deemed adequate 
to satisfy demand for 20 yr. 

The World Bank-LME lead price forecast (IS) 
predicts constant 1981 dollar lead prices of $0.29 per 
pound in 1985. $0,358 in 1990, and $0.38 in 1995. The 
$0.38-per-pound estimate for 1995, if reasonably accu- 
rate, would indicate that 84 pet of the 26.4 million t 
of lead metal from the mines and deposits evaluated as 
primary lead operations could potentially be produced 
and earn a 15-pct DCFROR for each respective opera- 
tion. The United States, with the largest low-cost re- 
source, appears to have a comparative advantage over 
the rest of the world industry. 

Total world primary zinc demand is estimated to 
grow by 2.5 pet a year through 2000 U), which is 
slightly higher than the 2.2-pct annual growth rate 
projected for the U.S. demand. This would make cumu- 
lative primary demand from 1981 through 2000 equal 
to 23 million t in the United States and 143 million t 
for the total world. Because the demonstrated recover- 
able resources of zinc in market economy countries 
alone equals almost 154 million t, the current zinc 
resource is adequate to meet demand through the year 
2000 At 1981 market prices, however, the available 
economic tonnage of zinc from market economy coun- 
tries equals only 56.1 million t, of which 2.7 million t 



is in the United States. Superficially, this discrepancy 
between cumulative demand and lower cost potential 
supply indicates that the price for zinc, in real terms, 
would have to go up dramatically in order to satisfy 
cumulative demand through 2000. 

This can be quite misleading, however, owing to 
the dynamic nature of resource estimates. This study 
is based on a static, conservative resource estimate for 
zinc based on 1981 data. No effort has yet been made 
to project potential zinc resources that may exist in 
2000. Zinc resource estimates have increased over time 
as new deposits have been discovered and as explora- 
tion programs continue at existing mines. For ex- 
ample, zinc resources in 1962 (lb) were estimated to 
equal 77.1 million t (11.1 million in the United States). 
This resource equaled a 17-yr supply of zinc at 1962 
consumption rates. Current resource estimates are 
deemed sufficient to provide at least a 20-yr supply. 

The point is that these resource estimates are 
based on current data, and are not meant to indicate 
that we are going to run out of a given commodity in 
20 yr. It is not unlikely that resource estimates for 
zinc in 2000 will indicate that resources are also 
deemed sufficient for a 20-yr supply of zinc. The key 
results of this study are not so much the aggregate 
tonnages presented, which are going to change on an 
almost annual basis anyway, but the relative distri- 
bution of resources between countries and the relative 
costs of production associated with these tonnages. 
The cun-ent lower cost producers will probably con- 
tinue to be the low-cost producers, particularly if any" 
significant new tonnage increases of zinc resources 
over the next 20 yr or so are additions to existing 
mines. This would suggest that the U.S. position in 
zinc production will remain weak or will weaken fur- 
ther owing to the small percentage of low-cost zinc 
potentially available from producing mines. Although 
the United States contains the largest potentially 
recoverable zinc resource in market economy countries, 
slightly less than 11 pet of this resource is from 
producing mines, and the balance from undeveloped 
deposits will be much higher cost to exploit than the 
zinc resources in other market economy countries. 

In summary, the results of the analyses indicate 
that zinc resources in market economy countries should 
at least be adequate to satisfy projected demand for 
primary zinc through the balance of this century. 
The study suggests that the comparative disadvantage 
faced by the U.S. zinc industry will probably intensify 
owing to the relative quantity of lower cost zinc re- 
sources in other countries, especially Canada, Aus- 
tralia, and Mexico. One World Bank price forecast for 
zinc (13) predicts that, in constant 1981 dollar terms, 
the price of slab zinc on the London Metal Exchange 
(LME) will drop to $0.36 per pound in 1985, and 
then rise to $0,419 in 1990. and to $0.45 in 1995. Such 
a gradual rise in constant dollar prices for zinc would 
indicate that the industry will remain fiercely com- 
petitive throughout the balance of the century, and 
profitability will remain an elusive goal for many pro- 
ducers if the long-run constant dollar price for zinc 
remains at such a low level. 



40 



CONCLUSIONS 



The demonstrated resources of lead and zinc ore 
comprising 235 mines and deposits in market economy 
countries evaluated for this study amount to approxi- 
mately 4.3 billion t of ore containing 221 million t of 
zinc and 97 million t of lead. Of these amounts, ap- 
proximately 154 million t of zinc and 70 million t of 
lead are estimated to be recoverable. These demon- 
strated resources are sufficient to satisfy projected 
demand through the balance of the century. Further- 
more, as new lead and zinc deposits are discovered, 
and as exploration programs at existing mines con- 

e, it is likely thai itrated resource estimates 

will continue to increase over time. 

Low prices for both lead and zinc have served to 
make the financial position of producers more pre- 
carious over the past several years. Several marginal 
producers have shut down permanently and other high- 
cost producers will likely follow suit over the next few 
years if prices continue to remain at low levels. The 
109 producing mines evaluated as primary zinc mines 
have a weighted-average estimated total production 
cost (including a 15-pct DCFROR) of $0.34 per pound. 
Total potential zinc production from these mines 
amounts to 61.8 million t, with 44.8 million t potentially 
available at estimated cost levels below the January 
1981 market price of $0.41 per pound. The United 
States appears to be at a competitive disadvantage, 
with only 454,000 t of zinc potentially recoverable 
below a long-run total cost of $0.41 per pound, and a 



weighted-average estimated total cost of $0.58 for 
the 4.14 million t estimated to be recoverable from 
U.S. producing mines. 

A total of 79.3 million t is potentially recoverable 
from the 77 undeveloped zinc deposits evaluated in 
market economy countries with a weighted-average 
total cost of $0.74 per pound. Only 1.85 million t (2.3 
pet of the total) is estimated to be recoverable below 
$0.41 per pound. The 36.1 million t of zinc potentially 
recoverable from undeveloped deposits in the United 
States has an estimated weighted-average total cost 
of $0.86 per pound. 

It is likely that U.S. dependence on imported slab 
zinc will continue to increase in the future, although 
stable supplies are virtually assured from Canada, 
Australia, and Mexico. 

The cost picture for producing lead mines in the 
United States looks somewhat brighter. Nine U.S. 
mines account for 72.8 pet of the total potential ton- 
nage from the 22 producing mines evaluated for this 
study, and have a weighted-average estimated total 
cost of $0.27 per pound. The non-U. S. producing mines 
have a weighted-average total cost of $0.30 per pound. 
The five undeveloped U.S. deposits evaluated appear 
to have a minor cost advantage over the three non- 
U.S. deposits, although none of the eight deposits has 
an estimated long-run average total cost that is less 
than the January 1981 market price of $0.34 per pound. 



REFERENCES 



1. U.S. Geological Survey and U.S. Bureau of Mines. 
Principles of a Resource/ Reserve Classification for Miner- 
als. U.S. Geol. Surv. Circ. 831, 1980, 5 pp. 

2. Clement, G. K., Jr., R. L. Miller, P. A. Seibert, L. 
Avery, and H. Bennett. Capital and Operating Cost 
Estimating System Manual for Mining and Beneficiation 
of Metallic and Nonmetallic Minerals Except Fossil Fuels 
in the United States and Canada. BuMines Spec. Publ., 
1980, 149 pp.; also available as STRAAM Engineers, Inc. 
Capital and Operating Cost Estimating System Handbook 
— Mining and Beneficiation of Metallic and Nonmetallic 
Minerals Except Fossil Fuels in the United States and 
Canada (contract J0255026), 1977, 374 pp.; available 
from U.S. Government Printing Office, stock No. 024- 
004-0215-6. 

3. Woodbury, W. D., and J. A. Rathjen. Lead. BuMines 
Mineral Commodity Profile, 1983, 17 pp. 

4. Jolly, J. H. Zinc. BuMines Mineral Commodity Pro- 
file, 1983, 18 pp. 

5. Davidoff, R. L. Supply Analysis Model (SAM) : A 
Minerals Availability System Methodology. BuMines IC 
8820, 1980, 45 pp. 

6. Stermole, F. J. Economic Evaluation and Investment 
Decision Methods. Investment Evaluations Corp., Golden, 
CO, 1974, 443 pp. 



7. Kilgore, C. C, S. J. Arbelbide, and A. A. Soja. Lead 
and Zinc Availability — Domestic. A Minerals Availability 
Program Appraisal. BuMines IC 8962, 1984, 30 pp. 

8. Jensen, M. L., and A. M. Bateman. Economic Mineral 
Deposits. 3d ed., 1981, 593 pp. 

9. Brown, D. H., and A. Lust. World Directory: Lead 
and Zinc Mine and Metallurgical Works. MRI 79/5, 
Mineral Policy Sector, Internal Report. Energy, Mines 
and Resources of Canada, 1979, 78 pp. 

10. Cotterill, C. H., and J. M. Cigan. Survey of World 
Lead and Zinc Production. Paper in AIME World Sym- 
posium on Mining and Metallurgy of Lead and Zinc. 
AIME, New York, v. 2, 1970, p. 15. 

11. U.S. Bureau of Mines. Silver. Ch. in Mineral Com- 
modity Summaries 1984. Pp. 140-141. 

12. Moulds, D. E. Lead. Ch. in Mineral Facts and Prob- 
lems, 1965 Edition. BuMines B 630, 1965, pp. 489-509. 

13. The World Bank. Biennial Review of Commodity 
Price Forecasts, Volume 3: Metals and Minerals. The 
World Bank, Washington, DC, 1983, 244 pp. 

14. Schroeder, H. J. Zinc. Ch. in Mineral Facts and 
Problems, 1965 Edition. BuMines B 630, 1965, pp. 1083- 
1104. 

15. Purser, W. F. C. Metal Mining in Peru, Past and 
Present. Praeger Publ., New York, 1971, 329 pp. 



41 



APPENDIX —GEOLOGIC CHARACTERISTICS OF MAJOR LEAD AND ZINC DEPOSITS 

IN MARKET ECONOMY COUNTRIES 



AUSTRALIA 

Of the 15 Australian deposits evaluated for this 
report, 6 contain significant amounts of recoverable 
copper and all of the deposits have silver present in 
important recoverable quantities. The major Aus- 
tralian lead and zinc deposits occur in two main dis- 
tricts: Mount Isa and Broken Hill. Mount Isa is the 
larg- ralian lead-zinc deposit, located in west- 

central Queensland. Mineralization occurs as syngene- 
ic deposition in the Urquhart shale formation of the 
Lower Proterozoic Mount Isa Group sediments. Ga- 
lena, sphalerite, and pyrite form closely spaced, con- 
cordant bands grouped to form 14 distinct ore bodies 
in an en echelon pattern. The nearby Dugald River, 
Hilton, and Lady Loretta deposits are genetically 
similar to the Mount Isa deposit. 

The McArthur River deposit is a large explored 
deposit located 100 km south of the Gulf of Carpen- 
taria in the Northern Territory. The stratiform de- 
posit is unme*amorphosed and occurs near the center 
of the McArthur Group, a sequence of dolomitic 
sedimentary rocks of Middle Proterozoic Age. Fine- 
grained sphalerite, galena, and other sulfides occur as 

minations in carbonaceous, potassic, dolomitic, 
and pyritic shales. A small amount of silver is asso- 
ciated* with the galena and marcasite; arsenopyrite 
and chalcopyrite are also present. This deposit may 
possibly be related genetically to the Mount Isa-type 
deposits. 

The Broken Hill district in western New South 
Wales occurs within the Willyanna Complex, a system 
of foliated metamorphic rocks of the Proterozoic Era. 
The deposit is stratiform type with lens-shaped ore 
bodies containing sphalerite and galena with minor 
pyrrhotite and marcasite. Ore is currently extracted 
by three operations in the Broken Hill deposit: North 
Broken Hill Holdings Ltd., Vaw Broken Hill Consoli- 
dated Ltd., and Zinc Corporation mines. 

Volcanogenic massive sulfide deposits are found 
at Woodla.n, N ith Wales; Teutonic Bore in 

ern Australia; Que River and Rosebery in Tas- 
mania; and Benambra in Victoria. The C.S.A. deposit 
in the Cobar mining district of western New South 

•s is also a massive sulfide deposit localized in 
siltstones of the Upper Silurian age Cobar Group sedi- 
ments, which lie on the west limb of an extensively 
folded anticlinal structure. 



CANADA 

A total of 42 Canadian lead and zinc deposits were 
evaluated for this study. These deposits fall into three 
general geological classifications: limestone replace- 
ment, shale-hosted, and volcanogenic massive sulfide, 
stone replacem* eferred to as Missis- 

sippi Valley type df-r, onsist oi lime- 

stone or dolom formations that have been 



mineralized by mineral-bearing fluids. Major ore min- 
erals are galena and sphalerite with minor occurrences 
of silver. The Pine Point. Prairie Creek, Great Slave 
Reef, Nanisivik. and Polaris deposits in the Northwest 
Territories are examples of limestone replacement 
ores. The Mel deposit in the Yukon Territory is also 
an example of a limestone replacement ore body. 

In the Selwyn Basin, Yukon Territory, numerous 
massive pyritic lead-zinc-silver deposits occur as near- 
ly horizontal stratiform, stratabound massive sulfide 
zones. In the Anvil Range, the sulfide mineralization 
is in a graphitic schist of Devonian age and is believed 
to have originally formed syngenetically with its host 
rocks. The Howard's Pass and Tom deposits are in a 
pyritic shale environment on the northern fringes of 
the Selwyn Basin. The Sullivan ore body in southern 
British Columbia and the Cirque deposit in north- 
central British Columbia are also shale hosted-type 
deposits. 

Volcanogenic massive sulfide type lead-zinc de- 
posits are formed in a marine environment in the 
vicinity of volcanic vents. Deposition takes place at 
the water-sediment interface to form a zoned, poly- 
metallic sulfide deposit. Some stockwork deposition 
takes place in the fractured and brecciated volcanic 
rocks around the vent. The Kidd Creek and Geco 
deposits in Ontario, and Brunswick No. 12 and Heath 
Steele deposits in New Brunswick, are prime examples 
of this type of deposit. 

INDIA 

Three deposits containing lead-zinc mineraliza- 
tion and one containing copper with lead-zinc by4 
products were evaluated. Lead-zinc mineralization 
forms either stratiform, massive complex sulfide de- 
posits or stratabound, vein-type deposits. The strati- 
form deposits generally contain high ore grades, 
whereas the stratabound vein-type are lower in grade. 
The deposits in the Zawar Group occur in low-grade 
metamorphosed graywackes, phyllites, dolomites, and 
quartzites, with associated minor occurrences of un- 
metamorphosed intrusive igneous rock. The lead-zinc 
ore bodies are believed to be of hydrothermal origin. 
Mineralization consists of sphalerite, pyrite, and ga- 
lena in association with chalcopyrite, pyrrhotite, and 
arsenopyrite. Silver and cadmium are associated with 
the ore minerals. 

The Ambaji copper deposit has relatively high 
lead and zinc contents. The main ore mineral at Am- 
baji is chalcopyrite with lesser amounts of the copper 
minerals chalcocite and covellite, plus galena, sphale- 
rite, and pyrite. 

IRELAND 

Five lead-zinc deposits, three in northeastern Ire- 
land, one in north-central Ireland, and one in we tern 



42 



Ireland, were evaluated. Sphalerite, pyrite, and galena 
are common sulfide minerals. Gangue minerals consist 
of dolomite, pyrite, barite, quartz, calcite, and marca- 
site. 

The stratabound Bula and Tara deposits in north- 
eastern Ireland occur in Pale Beds of Carboniferous 
age, composed of silty and oolitic limestones and dolo- 
mites, enveloping the stratabound sulfide mineralized 
zone. In the lower section of the ore body, mineraliza- 
tion forms five separate lenses that converge in the 
upper ore body to form a single massive sulfide ore 
body more than 60 m thick. Three major faults dissect 
the ore body. Folding and faulting of the host rocks 
have produced a complex ore body shape. 

The Sabina-Tatestown deposit in northeastern 
Ireland is stratiform, occurring in (lower carboni- 
ferous) argillaceous limestones. An east-west fault 
parallel to the ore body displaces the mineralized zone 
70 to 100 m. 

In north-central Ireland, the Ballinalack deposit 
is a stratabound ore body within Reef Limestone of 
lower Carboniferous period. The lead-zinc mineraliza- 
tion fills fractures and cavities within the Reef Lime- 
stone to form a few diffuse lenses. 

Mogul deposit, in western Ireland, has two strati- 
form ore bodies formed within Waulsortian carbonates 
and a lower, stratabound ore zone contained within 
lower dolomites of Tournaisian age. The lower zone is 
delimited by a northwest-trending fault. 



JAPAN 

Nine lead-zinc deposits were evaluated in Japan; 
one deposit is located on Hokkaido, four in north 
Japan, and four in central Japan. Two of the deposits 
are primary copper deposits with lead-zinc byproducts. 

The stratabound Kuroko or "black ore" type de- 
posits of Japan are commonly regarded as the classic 
type of volcanogenic polymetallic (copper-lead-zinc- 
silver) massive sulfide (and sulfate) deposits, genetic- 
ally related to explosive felsic volcanism of Miocene 
age. Mineral assemblages and mineral zoning are simi- 
lar among typical Kuroko deposits. In the stratiform 
ore bodies, the upper half is typically rich in galena, 
sphalerite, and barite (black ore), while pyrite and 
chalcopyrite are dominant in the lower half (yellow 
ore). Underlying the stratiform ore bodies are lower 
grade stockwork ore bodies, characterized by dis- 
seminated and stockwork-type mineralization of pyrite 
and chalcopyrite distributed in an irregular funnel 
shape in felsic lavas and pyroclastics. The stockwork 
ore is generally strongly silicified and is also called 
siliceous ore. 

Along the Japan Sea, from Hokkaido to Kyushu, 
is a specific geologic province called the Green Tuff 
Region in which numerous Kuroko deposits occur. In 
this region, the volcanic rocks show a characteristic 
greenish color as a result of diagenetic and hydrother- 
mal alterations. Vein-type base metal as well as silver- 
gold deposits al-so occur in this region. Mines evaluated 
in this region include the Ezuri, Fukazawa, Hosokura, 
Kosaka, and Toyoha deposits. 

The geology of the Kamioka-Hida mountain re- 



gion consists of injection gneiss, acid and basic plu- 
tonic rocks (granite and metabasite), Jurassic sedi- 
ments, and intrusive Cretaceous stocks and dykes of 
granite porphyry and quartz porphyry. The character- 
istic feature of the Hida Complex gneissic rocks is the 
large number of intercalcerated limestone beds. Lime- 
stone beds are dragfolded within this complex of meta- 
morphosed Precambrian to Paleozoic geosynclinal 
sediments are the host rocks for the numerous ore 
bodies exploited at the Kamioka Mine. 



MEXICO 

The most important producing State for lead and 
zinc in Mexico is Chihuahua, followed by Zacatecas. 
Guerrero, San Luis Potosi, and Hidalgo. In the State 
of Chihuahua, the Santa Barbara ore bodies consist of 
veins of sulfide mineralization contained in fissures 
and fractures in shale country rock and andesitic in- 
trusives. Sulfide minerals are sphalerite, galena, chal- 
copyrite, and argentite. 

In the Parral District of Chihuahua, lead-zinc- 
silver ore bodies occur c.s veins in normal-type faults. 
The veins are more or less continuous along the strike 
of the fault. An oxidation zone to 300 m (below sea 
level) overlies an enrichment zone and a sulfide zone. 

In northern Coahuila, the La Encantada District 
has two major ore bodies and several minor ore bodies 
occurring in a mineralized trend within limestone 
country rock. Mantos, chimney, vein, and tabular 
shaped ore bodies are formed along limestone-skarn 
contacts. The mineralized zones are offset by a series 
of perpendicular faults. An abundance of iron oxides 
and complex mineral assemblages characterize the La 
Encantada deposits. High-grade ore minerals are ce- 
russite, mimetite, acanthite, argentite, and some native 
silver. Low ore grade minerals consist of dominant 
hematite, magnetite, limonite, geothite, and malachite. 
Other minerals are smithsonite, anglesite, lead jaro- 
site, marmatite, hemimorphite, azurite, native copper, 
chrysocolla, and argentojarosite. 

The Taxco Unit in Guerrero, Mexico, comprises 
three mines. Ore deposits occur as vein fissures or as 
replacement ore bodies in limestone beds. Lead-zinc 
mineralization is higher in the vein fissures than in 
the replacement ore bodies. Mineralization zones in- 
clude quartz, argentiferous galena, and sphalerite. 

Two major ore bodies are located in the Sierra 
Madre Oriental of southeastern Oueretaro. The ore 
zones occur in tactite associated with intrusive igneous 
rocks. Both massive and disseminated mineralization 
are present. Ore minerals are sphalerite, galena, chal- 
copyrite, pyrargyrite, proustite, polybasite, and argen- 
tite. 

Deposits of the Charcas District in the El Alti- 
plano region of San Luis Potosi are mineralized frac- 
ture fillings and replacement bodies associated with 
intrusive rocks that penetrated limestone formations. 
Paleozoic and Mesozoic sedimentary rocks were pene- 
trated by middle Eocene intrusives. Dykes and small 
fissures near limestone-porphyry contacts and peri- 
pheral fissures within the Cuesta del Cura Formation 
contain mineralized replacement bodies. The most im- 



43 



portant ore bodies are located on the San Bartolo and 
the San Fidel Faults. Sulfide minerals are sphalerite, 
argentiferous galena, chalcopyrite, and pyrite. 

In the San Martin District in Zacateeas. Mexico, 
a stratabound copper-zinc deposit occurs in the Upper 
Cretaceous Cuesta del Cura Limestone with minerali- 
zation in veins and replacement zones. A silver-lead- 
zinc deposit occurs as disseminations, stringers, and 
bands in a folded sequence of graywackes. Mineraliza- 
tion consists of sphalerite, chalcopyrite, bornite. ar- 
senopyrite. pyrrhotite, pyrite. tremolite. quartz, cal- 
cite. fluorite. and minor amounts of argentite. native 
silver, tetrahedite. and scheelite. 

In one of Mexico's oldest silver destricts. the 
Fresnillo deposits in Zacateeas occur as veins, stock- 
works, mantos. and chimneys. The sulfide zone contains 
quartz, pyrite. arsenopyrite, pyrrhotite. sphalerite, 
galena, chalcopyrite. pyrargyrite, proustite, polybasite, 
argentite. and calcite. 

A number of small lead-zinc deposits and deposits 
containing lead-zinc as byproducts are located in the 
Mexican States of Aguascalientes. Durango, Hidalgo, 
Jalisco. Mexico. Michoacan, Xuevo Leon, Oaxaca. 
Puebla, Sinaloa, Sonora. and Tamaulipas. 



MOROCCO 

The Zeida. Touissit. and Aouli-Mibladen deposits 
are primarily lead producers: Djebel Aouam and Sidi 
Lachen are lead deposits with byproduct zinc, and Bou 
Madine is a zinc-lead-silver deposit. Zeida, the largest 
lead deposit, lies unconformably on a horizontal plane 
above Moulouya granite. Overlying the ore zone are 
argillaceous beds and red mudstones. Host rocks are 
arkosic sediments consisting of granular quartz and 
feldspar. Galena and cerussite are major lead minerals 
and minor quantities of anglesite, pyrite, and chal- 
copyrite are also present. 



PERU 

Lead and zinc mineralization occurs primarily in 
the Cordillera Occidental region of the central Sierra, 

dated with three of five major geologic belts in 
central Peru: Central Andean Mesozoic Belt, Eastern 
Paleozoic Belt, and Cenozoic Volcanic Belt. Minerali- 
zation is almost alwavs associated with large longi- 
tudinal faults and intrusive bodies. Deposits are 
localized as mineralized faults, breccia pipes, and re- 
placement mantos in adjacent limestone beds. 

Terro de Pasco is the largest of the Peruvian 
lead-zinc mine-, accounting for over 50 pet of the lead 
and over 35 pet of the zinc resource in Peru. Situated 
on the line of a major longitudinal fault, it is bounded 
to the east by the Pucara limestone and to the west by 
the Paleozoic Excelsior formations. The mineralization 
13 in the debris of a volcanic blasthole (15).* 

Antamina is a low-grade, large-tonnage copper- 
zinc-silver deposit localized in a tactite zone surround- 



1 Italic number- In parenttie*et refer to Items In the list of refer- 

<1|X. 



ing a quartz monzonite porphyry intrusion. The host 
rock is predominantly carbonate with minor shale of 
Cretaceous age. Approximately 19 pet of the Peruvian 
zinc resource is contained in this deposit. 

The remaining deposits evaluated are primarily 
silver-zinc-lead deposits related to limestone replace- 
ment mantos or vein fillings associated with limestone, 
igneous intrusives and volcanic beds. 



PORTUGAL 

The Aljustrel and the Neves-Corvo deposit (which 
was not evaluated for this study"), located in southern 
Portugal contain lead, zinc, copper, and silver in re- 
coverable amounts. Both deposits are massive sulfide 
lenses contained in tuffaceous rocks. Aljustrel. the 
larger deposit, consists of five ore bodies. Mineraliza- 
tion is contained within a schistose sericitic rock for- 
mation. A number of faults including the Messejana 
Fault displace the mineralized zone. Ore minerals are 
massive pyrite with fine-grained, disseminated chal- 
copyrite, sphalerite, and bornite. 



REPUBLIC OF SOUTH AFRICA 

The principal lead-zinc deposits in the Republic of 
South Africa are the Prieska, Broken Hill-Black 
Mountain, and Gamsberg deposits. The Prieska de- 
posit is a copper-zinc deposit while the Broken Hill- 
Black Mountain complex supplies lead and zinc, and 
Gamsberg is primarily a zinc deposit. The Broken Hill- 
Black Mountain deposit in Cape Province comprises 
two massive sulfide ore bodies that were formed on 
opposite flanks of an Archean complex southeast 
plunging anticline. Mineralization is believed to be 
syngenetically related to highly metamorphosed vol- 
canics. Major sulfides are pyrite, chalcopyrite, sphale- 
rite, pyrrhotite, and minor amounts of arsenopyrite, 
galena, magnetite, neodigenite, and molybdenite. 
Gamsberg is a high-grade zinc deposit similar to the 
Broken Hill-Black Mountain deposits. 



SPAIN 

Of the six deposits evaluated, the Aznalcollar and 
Sotiel deposits consist of copper mineralization with 
byproduct lead and zinc; the Cartagena, Reocin, and 
Rubiales deposits contain zinc ore with byproduct 
lead; and Linares (El Cobre) contains primarily lead 
mineralization. 

Aznalcollar is located in southwest Spain. The 
local geology is characterized by folding and deformed 
stress zones of Hercynian orogeny on the east limb 
of an anticline. The underlying sequence consists of 
Lower Cambrian carbonates I limestone and dolomites) 
and fine-grained clastic rocks. The vertical ore body 
has intricate drag folds and some brecciation has 
occurred. Mineralized limestone beds within the min- 
eralized area form ladderlike rungs across the vertical 
ore body. Minerals are sphalerite, fine-grained galena, 
and some pyrite and chalcopyrite. 



44 



Spain's largest lead-zinc deposit is located near 
Cartegena on the southeastern coast of Spain. The 
lead-zinc mineralized zone occurs in a Miocene se- 
quence of pebbly mudstone beds. Mineralization fills 
cavities and pebble-shaped voids. Ore minerals are 
marcasite, pyrite, galena, sphalerite, and quartz. 

SWEDEN 

The Zinkgruven and Garpenberg Mines, located in 
central Sweden, extract ore from large complex poly- 
metallic sulfide ore bodies. Ore mineralization occurs 
in highly metamorphosed Precambrian country rocks 
composed mostly of siliceous volcanics. 

The Vassbo-Guttusjo lead-zinc mineral deposits in 
west-central Sweden are stratabound, occurring in thin 
sequences of Lower Cambrian age sandstones. Diabase 
intrusions dissecting the Precambrian basement con- 
trol the distribution of the ore bodies. 

In northwestern Sweden, bordering the eastern 
slope of the Caledonian Mountains, the Laisvall lead- 
zinc deposit is stratabound with three major ore 
zones : a lower ore-bearing sandstone, a middle barren 
or low-grade sandstone, and an upper ore-bearing 
sandstone. These flat-lying ore bodies form two thin 
sheets in the lower and upper layers of the quartzitic 
sandstone horizons of upper Precambrian-Cambrian 
rocks. 

The Stekenjokk copper-lead-zinc deposit in the 
Skellefte District of central Sweden is a massive py- 
ritic ore body occurring in Koli metasediments anc 1 
metavolcanics. The dominant host rock of ore is ai 
altered quartz-keratophyre. Predominant sulfide min- 
erals are galena, sphalerite, chalcopyrite, and pyrite. 
Other minerals present are barite, fluorite, calcite, and 
sericite. 

UNITED STATES 

A detailed geologic summary of lead and zinc 
deposits in the United States (7) has been published. 
This report will focus only on the two most important 
areas in the United States; southeast Missouri lead 
deposits and the eastern Tennessee zinc deposits. 

Missouri 

The lead deposits in southeastern Missouri occur 
on the flanks of a dome in a series of Upper Cambrian 
sedimentary rocks that encircle the St. Francois 
Mountains. Although there is some mineralized rock in 
other Paleozoic strata, most of the ore bodies occur in 
the brown dolomite of the Bonne Terre Formation. 

Ore deposits are stratiform and the minerals 
generally occur either in replacement of disseminated 
deposits, veinlets, or fillings in open spaces. Although 
the deposits consist mostly of lead-bearing minerals, 
enough zinc is present for six of the seven producing 
mines to be included among the top zinc producers in 
the United States. Small amounts of copper, nickel, 
cobalt, and cadmium also occur in the deposits but only 
zinc, copper, and cadmium are currently recovered as 
byproducts. 



The Old Lead Belt, on the eastern flank of the St. 
Francois Mountains, is an area of extensive historical 
production but is almost mined out, and development 
is now centered in the more recently discovered Vi- 
burnum Trend to the west. All of the Missouri sites 
evaluated in this study are located in the Viburnum 
Trend except the Higdon and Bonne Terre Mines, 
which are in the Old Lead Belt. The Indian Creek 
Mine is not located in the main portion of the Vi- 
burnum Trend, but is considered to be in an offset 
portion of it. 

Tennessee 

All of the deposits in Tennessee, with the excep- 
tion of the Copperhill (Ducktown) Mines, are Missis- 
sippi Valley-type and occur in dolomite or limestone 
beds in either the Kingsport Formation and/ or the 
Mascot Dolomite of the Cambro-Ordovician Knox 
Group. 

The deposits evaluated for this study occur in 
either the central Tennessee-Kentucky area, the Copper 
Ridge District, or the Mascot-Jefferson City District. 
Strata are generally horizontal in the central Tennes- 
see-Kentucky region but dip moderately to the south- 
east in the other two districts. 

The minerals generally occur in breccia bodies 
that are very complex and irregular in shape, forming 
a netlike pattern around islands of barren rock. Indi- 
vidual breccia bodies located on different stratigraphic 
levels may be connected by vertical pipe-shaped breccia 
bodies (breakthrough ore bodies) also containing 
mineralized rock. All of the deposits are Mississippi 
Valley-type with sphalerite as the major zinc mineral; 
minor amounts of galena also occur. 

The Copperhill Mines are located in the Ducktown 
Mining District. For this study, the Boyd, Calloway. 
Cherokee, and Eureka Mines and the North and South 
Pits were included in the Copperhill evaluation. 
Minerals occur in metamorphosed massive sulfide 
accumulations in metamorphosed interbedded gray- 
wackes and mica schists in the Upper Precambrian 
Copperhill Formation of the Great Smoky Group. 
These rocks have been folded and faulted. There are 
two or possibly three series of beds that are favorable 
for mineralization, and many of the deposits occur 
where the favorable sediments have been thickened by 
folding. All of the deposits contain iron, copper, and 
zinc, with minor gold, silver, and lead. 



ZAIRE 

The Kipushi District of Shaba Province has the 
only major zinc-copper deposit of the country. The 
deposit is a replacement body in sedimentary (dolo- 
mitic) formations of the Kundulungu Series. The 
mineralized zone is located on the Zaire-Zambia border 
along a transverse fault crossing the northwest strike 
of Kipushi anticline. The ore mineralization was 
formed in two stages. The first stage mineralization 
consists of pyrite-arsenopyrite-sphalerite and minor 
galena. The second stage has a cobaltiferous chalcopy- 
rite phase and an argentiferous bornite phase. 






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